Impossible
by subtract
Summary: The Doctor finds himself alone again, now that all his companions have left. But some unknown force has pulled the TARDIS into a parallel world where, supposedly, magic exists. But magic is impossible...isn't it?
1. Chapter 1

**A/N *has tiny little first fanfic party, then puts away balloons and confetti* Okey dokey, now that THAT'S out of the way I can start. ;) The story happens right after Journey's End, so the Doctor's by himself. Again. Poor guy. **

CHAPTER ONE

The Doctor stood in the middle of the TARDIS, staring down at the metal grating. Once again, he was alone. It had hurt to watch everyone walk away from the TARDIS, more than he cared to admit even to himself. They didn't need him anymore- they all had someone else. Sarah Jane had her son. Martha and Donna had their families. Rose had the metacrisis.

The Doctor sighed bitterly at the memory of Rose and the metacrisis kissing on Bad Wolf Bay. It was painful…so painful to know that he could never be with her, but at least she was happy.

And Donna…wiping her memory had been one of the hardest things he'd ever done. The DoctorDonna. She had been so happy…but he could never see her again, for her own safety.

Really, he couldn't see anyone again. Every time he did, it got his hopes up, thinking that maybe he didn't have to feel so alone anymore. And every time, his hopes crashed harder. Seeing everyone together and then having them leave again had almost destroyed him inside.

"What were you expecting?" he said loudly. "Did you think they would all just drop their lives to come with you? They've moved on. It's time you did too. Stop being ridiculous and get on with life." He was a little surprised as his voice cracked halfway through.

The TARDIS mentally nudged the Doctor in a comforting way. He smiled and leaned against one of the coral-like spires. "Sorry, girl. That was a bit loud, wasn't it?" He patted the column affectionately. If anything, at least the TARDIS was always going to stick around.

Pushing away from the column, the Doctor walked to the main console, fingers lingering over some switches. He fiddled with some of the controls, not sure what to do. All he knew was that he really, really didn't want to be on Earth right now.

The TARDIS was humming softly in his mind. He smiled ever so slightly as he recognized the Gallifreyan love song. That was where he really wanted to be- back on Gallifrey, with his family and friends. Right now he would have given anything just to see it again, even from a distance. But Gallifrey was gone, just like all the others. And that hurt more than anything, because he had destroyed it.

Sighing, he twisted the main control dial to the 'random' setting and pulled the lever to start the TARDIS up. Flicking switches to the right positions, twisting knobs to the coordinates the TARDIS had chosen, and pushing buttons that were flashing, probably for a reason…he did everything without any of his usual manic energy. Even the shaking floor refused to excite him.

With the whirring sound that the Doctor enjoyed, the TARDIS flew out of the time vortex and appeared…somewhere. Swiveling the outer monitor over so he could take a look outside, the Doctor was surprised to see the flat expanse of outer space. Raising an eyebrow, he walked to the front doors and swung them open. He gasped as light flooded the TARDIS and flung his arm over his eyes. As his vision adjusted, he slowly lowered his hand.

The impenetrable shields of the TARDIS were filtering the impossibly bright rays of light streaming from the beautiful scene. The TARDIS was suspended inside a shining cloud of gas that was light years wide.

"The Horse-head Nebula?" the Doctor guessed, judging by the distinctive horse-shaped column rising above him. Over there- he could see where all the light was coming from. The swirling clouds had been drawn together to form a brand new star. Technically speaking, he should have been fried to a crisp by now, but the TARDIS's shields were siphoning the excess heat from the star and converting it into psionic energy.

"You brought me to watch a star being born," the Doctor said, quieter this time. The TARDIS hummed again, projecting a feeling of happiness and peace into his mind. No, it was more than that- the TARDIS was sending him hope. As he let the TARDIS soak his mind with the hope that new life always brings, he began to feel some of his old energy returning.

All of a sudden, he began to pick up another presence in his mind, besides the one of the TARDIS. Shaking his head to try and clear it, the Doctor stumbled away from the doors and back towards the consol. The TARDIS whirred worriedly in his head.

_Are we feeling lonesome, Doctor? _The presence said, speaking in a low, raspy voice that sounded like nails on a chalkboard. The Doctor gritted his teeth and pressed his hands against his head as the voice burrowed itself deeper into his mind.

"Who are you? What do you want?" the Doctor said through his clenched teeth.

_Is that all, Doctor? Not even an introduction from you? Not even a hello? Even a death threat would have been nice…oh, but you're a pacifist now, aren't you? Always trying to protect life._

"Well, an introduction would be a bit redundant now, since you obviously know me so well," the Doctor said sarcastically. "How about you answer _my_ question now: who are you and what are you doing in my head?"

_Oh, Doctor, surely you can do better than that. You're famous across the galaxies for getting answers all on your own. Why don't you try and figure me out for yourself, instead of just taking the easy route out._

"Get out of my head," the Doctor said. He could feel the muted voice of the TARDIS pushing against the force embedded in the Doctor's mind.

_My, your friend is a pushy one, Doctor! _The voice laughed. _And yet, even with your ship around…you still feel alone. Wouldn't you like to just give up and leave this universe completely? _

"You don't know me so well after all, then. I'm the Doctor- I don't give up. Leave the TARDIS alone."

_I am inside your head, Doctor. I know everything that you are feeling- oh my. Is that…fear that I sense? The infamous Doctor, afraid of the voices inside his head? _The voice laughed again, setting the Doctor's teeth on edge as the terrible cackling echoed in his mind.

"Leave. Now," the Doctor spat.

_Where ARE your manners, Doctor? I at least remember mine- an intelligent guest knows when he is unwelcome. I shall take my leave for now- but remember, Doctor, I know you. I know what you will think, what you will say, and what you will do. You cannot ever- and will not ever- escape from me!_

The Doctor gasped as he felt the voice pull itself from his head. As soon as she could, the TARDIS hummed loudly in his head, to reassure him she was back. The Doctor ran to the console and typed in a string of commands.

"Scan for life onboard," he said to the TARDIS. He was setting the computer to track any heartbeats, any electric pulses, and any abnormally large concentrations of high molecular activity. He didn't know what sort of being had been inside his head, but he did know that he didn't want it interfering with his TARDIS.

The computer came up with a result: only one living being was onboard the TARDIS. It was just him. Whatever had entered his brain had come and gone.

The Doctor exhaled slowly and sat down heavily on the metal grates. "Well…that was all a bit…Harry Potter-ish," he said, to try and lighten the tension both he and the TARDIS were feeling. He half-smiled when he remembered Martha as she coined the 'Harry Potter-ish' phrase, back when they had met Shakespeare.

The Doctor stood up again, striding over to the doors and closing them on the nebula still pulsing outside. "The Horse-Head Nebula and some freaky possessing being. You sure can pick 'em, sweetheart," he said, patting the TARDIS's console.

The TARDIS seemed a bit amused, but the other message she was sending the Doctor was much stronger- it was a warning. A warning of imminent danger.

"Hey, what's that for, old girl?" the Doctor said. "I'm not going to get into any kind of trouble just yet."

Right on cue, an alarm started blaring and the whole TARDIS shook violently. The sudden jolt sent the Doctor flying. As soon as the shaking stopped, the Doctor jumped to his feet.

"What the he-" Another rumble had him sprawled on the floor again. There was a short pause. The TARDIS transmitted her overpowering feeling of fear directly into his head. Then the ground beneath his feet came alive again, and the Doctor was slammed into the wall. The lights went down, except for the flashing alarms, and the white sparks flying from the delicate instruments powering the TARDIS.

The Doctor tried to pick himself up and run to the computer, but without anything to hold onto, and the jolts steadily becoming stronger and more frequent, he was being tossed around like a rag doll. There was smoke rising from the console, and the alarms had reached an almost deafening pitch. It was so loud and confusing, the Doctor could barely hear the TARDIS shouting in terror.

Suddenly, the doors of the TARDIS swung open, and the momentum from being thrown around sent the Doctor tumbling head over heels first across the steel floor and then… was that grass he was rolling down?

As the Doctor rolled, he managed to pick out a few important details: one, he was no longer in the TARDIS, and two, whatever he was rolling down was steep and covered in grass.

After a few seconds of merciless tumbling, the Doctor's momentum wore down and he rolled to a stop. Completely dizzy and out of sorts, the Doctor could barely make out the sight of the hill he had just rolled down. His vision was spinning wildly, so it took him a while before he was able to catch his breath again and push himself up to a sitting position.

Where was he? The Doctor squinted up at the sun- sun, singular. Blue sky, faint white cirrus clouds. Judging by the feel of the planet beneath him, the planet was at about a 14 degree tilt with the sun, and was turning on…a 24 hour schedule.

The Doctor's eyes widened. Sweet Rassilon- he was back on Earth!

Just has he had reached this conclusion, the Doctor was very surprised to have something that felt suspiciously like wood wrap around his ankle. Looking down, he just had time to register that a _branch was grabbing his leg_ when whatever had grabbed him pulled him straight up into the air.

The Doctor yelled as the ground disappeared beneath him. Trying to crane his neck around, he managed to get a glimpse of his attacker.

It was…a tree. Somehow, an Earth tree that looked to be like a hybrid species between an oak and a willow had…come to life and had attacked him.

Maybe it wasn't a tree at all. The branch hoisting him in the air was shaking him violently. The Doctor could feel his teeth chattering as his lower jaw kept slamming into his upper one. He just managed, through some stroke of luck, to get his hand inside his pocket and pull out his sonic screwdriver. The tree wouldn't stop shaking him, which made getting a read-out difficult. The Doctor got his chance when the tree paused for a second- he twisted up and jabbed the sonic screwdriver into the wood. The tree stayed still for a moment, and then proceeded to try and whack the Doctor with its other branches.

Narrowly ducking out of the way, the Doctor just missed having his head chopped off by the tree's vicious limbs. Setting 1249K- it was supposed to freeze any plant life form alien to Earth. The Doctor groaned. Yep- somehow, this tree really was an Earth tree.

"WHO'S- BEEN SCREWING-WITH THIS TREE'S-GENETIC SEQUENCE?" he yelled angrily, punctuating each word as he tried to avoid the swinging branches. Mother of Gallifrey, these humans could be so thick sometimes! It was so typical of them to just go out and genetically fashion this violent, killing machine of a tree!

The tree had resolved to try and smash him against the ground now. The Doctor just barely managed to grab the tree a little higher up before the branch crashed into the dirt.

As the tree swung him up again, the Doctor was twisting his sonic screwdriver as fast as he could to find the setting he wanted. 229J…229K…229L…229M!

The Doctor slammed the sonic screwdriver against the branch holding his ankle and pressed the button. The limb slowed down, and then stopped completely. The Doctor let out a sigh of relief that the screwdriver had worked. Then another branch tried to clobber him. Ducking at lightning speed, the tree almost managed to hit him.

The Doctor hissed in frustration. Only the one branch had been stopped. The rest of the tree could still kill him. Fantastic.

"Oi!" a voice yelled. "Who are you?"

Craning his head backwards so he could see the ground, he stared at two teenage boys- one with flaming red hair, the other with black hair and large round glasses. Both of them were pointing…sticks at him.

Had he stumbled into one of those tree-worshiping clans in the future? He didn't think they ever had those on Earth, but he might be wrong…

A stronger limb from the tree reached out and yanked the Doctor away from the immobilized one. The new branch lowered him halfway down to the ground before it began to shake him up and down. And, as luck would have it, the shaking made him loose his grip on the sonic screwdriver. The boy with red hair picked it up.

The two boy's faces were just centimeters away. Now the Doctor could see that one of them had a lightning bolt shaped scar over his right eye. The Doctor smiled cheekily.

"Hello kids, my name's the Doctor," he said. "Now can I have my screwdriver back?"


	2. Chapter 2

**A/N Yay, I got a review! :D Gracias! More are totally welcome, everybody ;) Oh, and I forgot this last time- DISCLAIMER: I don't own Doctor Who or Harry Potter. If I did, I wouldn't be writing fanfiction, I'd write a crossover into the original story.**

CHAPTER TWO

Harry had been having one of those rare days when absolutely nothing was wrong. He was a few weeks into his sixth year, and so far, nothing life threatening had happened. Considering his track record, this was quite an accomplishment.

He and Ron were enjoying the warm weather while it lasted. He was technically supposed to have his Astronomy class right about now, but last week Professor Aurora had gone to Hogsmade to pick up some supplies and never came back.

Unfortunately, the 'disappearances' were becoming more and more common, now that Voldemort had returned.

_Voldemort. _Even the thought of the Dark Lord sent shivers down his spine and made his scar prickle. As he reclined on the grass next to the lake, he couldn't help but shudder a little. Ron, fortunately, didn't notice. He was staring off into the distance, not even glancing at Harry.

Harry closed his eyes, trying to relax completely. Thinking about Voldemort had made the world seem colder, at least for him.

"Hey, Harry?" Ron said.

Harry grunted, keeping his eyes closed.

"Harry, what's that over there? It looks like something…burning."

Harry blinked and opened his eyes. "What? Where?"

"Over there by the Whomping Willow. Look, it's some little blue thing on fire."

Sitting up in interest, Harry squinted at the violent tree. Sure enough, there _was _something blue and on fire…falling from the sky…

"What the heck?" he murmured, standing up. "How did _that_ get here? I mean, doesn't Hogwarts have defenses set up against intruders or something?"

"No idea. Bet Hermione does, though," Ron said. "I bet it's something of Fred and George's. One of their experiments gone wrong."

Harry furrowed his eyebrows. For some reason, that didn't seem right to him.

"Want to take a look?" he said.

Ron shrugged. "Sure, why not?" He stood up and they set off towards the mysterious…thing.

As they got closer, Harry got more and more confused. Pointing to the top of the hill above the Whomping Willow, he whispered to Ron. "There it is!"

Ron squinted at where Harry's finger was pointing. "Blimey, it looks like one of those phone boxes. Except…blue."

Suddenly, Harry heard a voice shout out faintly high above him. _"Who's been screwing with this tree's genetic sequence?"_

Looking up, he was extremely surprised to see a slender man wearing a blue suit being attacked by the Whomping Willow's vicious branches. The man jabbed something at the limb holding his ankle, and it stopped abruptly.

Ron's eyes were as wide as dinner plates, so Harry could imagine his own eyes were just as big. The man seemed to have a wand, and had somehow broken into Hogwarts. A wizard with that kind of power would be very, very dangerous.

"Wand's out?" Harry said. Ron nodded and pulled his wand out of his jean's pocket. Harry did the same.

Another branch had ripped the man away from the frozen one and was shaking him up and down forcefully.

"Who do you think he is?" Harry said.

"Dunno. Let's find out," Ron said. Before Harry could stop him, he yelled out, "Oi! Who are you?"

The branch had lowered the stranger to just a few feet away. He started at the sight of them, and a strong shake made him drop his wand. Ron grabbed it and stared. Harry looked at it confusedly. The 'wand' was made of metal and was glowing blue at one end.

Now that the man was closer, Harry could see that he had a shock of brown hair, deep brown eyes, and…why was he grinning like a maniac?

"Hello kids, my name's the Doctor," the man said cheerfully. Ron and Harry could only stare. "Now can I have my screwdriver back?" he said. Before either of them could answer, the tree whisked him away back into the air.

The tree tossed the strange man around, then flung him with a huge amount of force at the ground. Even from a distance, Harry could hear the sharp crack as the man's head connected with the hard ground. He didn't get up again. The tree had released the man's ankle, and was preparing to grab him again.

"_Stupefy!_" Harry said quickly, aiming his Stunning spell directly for the right knot on the Whomping Willow's trunk. The tree became still.

The stranger was lying face down in the dirt. Harry and Ron knelt next to him and turned him onto his back. A trail of red blood leaked from his forehead.

"Is he dead?" Ron said, still holding the…'screwdriver'.

Harry felt for a pulse in the man's neck. To his surprise, the pulse was racing at double the speed it should have been.

"He's alive, just knocked out," Harry said. "His pulse is…really weird," he added, but Ron wasn't listening. He was holding up the man's 'screwdriver' and scrutinizing it.

"This isn't what regular screwdrivers look like, right Harry?" Ron said. Harry took the metal device from him and turned it over in his hands.

"Uh…no, no, not at all," Harry said absentmindedly. The device seemed to have a number of different settings, though it was currently set to "229M". He wondered what it was supposed to do.

"So who do you think he is?" Ron said, nodding towards the prone figure.

"Dunno. What _I _want to know is how he managed to break into Hogwarts. I mean, Dumbledore set up a million defenses, but he blew right past them all."

"Bet Hermione would know," Ron said for the second time that afternoon.

"Mmm-hmm," Harry agreed. "So…what should we do with him?"

"Ah…let's ask Hermione. She seems to know what to do in these kind of situations."

Harry couldn't disagree with that. "Well, go find her then, Ron!"

"Where is she?"

"Where do you think?" Harry asked sarcastically. "The Library," they chorused together. "You go find her and I'll stay here with this guy. Don't want him to wander off."

Ron sighed in exasperation, but got up anyway. "See ya in a minute, Harry," he said before running back towards Hogwarts, leaving Harry alone with the unconscious man.

…

Twenty minutes later, Ron reappeared with Hermione.

"What took you so long?" Harry asked.

"Hermione wanted to 'do some research'," Ron said in a disgruntled manner.

"Nice one, Hermione," Harry said sarcastically, but Hermione wasn't paying him any attention. She was already kneeling next to the stranger.

"Oh my word- Harry, who's _that_?" she said in a breathless voice.

"I don't know, that's why we got you," Harry said. "He broke into Hogwarts in some blue box thing."

"What? Broke into Hogwarts? That's impossible!" Hermione said, looking away from the man's face and stared at Harry as though he'd just suggested he wanted to help Hagrid breed a new set of Skrewts.

"Well, _he_ did," Ron said, nudging the man with his toe.

"That's…that's…" For once, Hermione seemed speechless.

"What should we do?" Harry asked her.

"I…I think we should see Hagrid. I mean, that's a nasty cut on his head, and we really can't ask him anything until he's awake, can we?" she said.

Ron, who was still standing, volunteered to go get Hagrid, leaving Harry and Hermione together.

"So, did he say what his name was?" Hermione asked Harry.

"Well, he did say something, but it was completely mental," Harry said.

"What did he say?"

"He said his name was…I dunno, 'The Doctor' or something," Harry said uncomfortably.

"…Oh."

They sat in silence for the next couple of minutes before Ron arrived with Hagrid.

"'arry? What's goin' on here?" Hagrid said.

"Hello, Hagrid, we…um, well, we wanted your…advice, I guess," Hermione started awkwardly, but Hagrid ignored her, instead crouching down next to the stranger.

"Who's this, then?" Hagrid said.

"We don't know, but…we think he broke into Hogwarts, but got caught by the Whomping Willow," Harry said.

Hagrid frowned. "Y'know, if I didn' know any better, I'd say this is Barty Crouch Jr."

Harry looked at the man and frowned like Hagrid. Now that he thought about it, the man did bear an unsettling resemblance to the Death Eater who had impersonated Mad Eye two years ago.

"Well," Hagrid said, slapping his thighs as he stood up. "We'd better get 'em back to my house. That cut's gonna need some lookin' after." He reached down and picked up the unconscious man. "Blimey, he's light," Hagrid said before setting off for his hut. Harry, Ron, and Hermione followed after him.

When they reached Hagrid's house, Hagrid set the man down on the tall bed and began to stoke his fire. The trio sat in Hagrid's giant chairs around the table, wisely not touching the tea or rock cakes Hagrid had set out for them.

Hagrid had just started to boil some bandages when all of a sudden, the man's eyes flew open and he sat bolt upright with a gasp, making everyone else jump in surprise.

"Where's the TARDIS?" was the first thing he gasped out. He stood up and looked around himself, oblivious to the fact that four sets of wide eyes were fixated on him. He finally seemed to notice that there were other people in the room. He stared at the three teenagers sitting at the table, then suddenly started grinning again.

"Oh, you're the two I met at the tree!" he said, grinning wildly. "Nice to see you again! Do you still have my screwdriver?" he asked Ron pointedly.

"Uh…Harry has it…" Ron said, gesturing towards Harry sitting at his left.

"Oh! Harry…what's your last name?" the man said. Harry blinked, the answered. "Ah, Potter. Harry Potter."

"Harry Potter…evil tree, Harry Potter, giant house…this seems really familiar," the man said. "Hold on a sec…" he closed his eyes and seemed to concentrate very hard on something. Then his eyes flew open again. "What?" he said quietly. He closed his eyes again. "There's something blocking my memory!" he said louder. "There's a closed door on Harry Potter!"

They all blinked. The man was pacing the floor, before stopping next to Harry. "Can I have my screwdriver?" he said in a voice little more than a whisper.

Harry was very confused at this point, but handed the stranger the metal device Ron had picked up. The man began to twist the end around and around, before announcing "Aha! 63D!" and pressing the screwdriver against his head.

"Um…excuse me sir?" Hermione said. "Well…first of all, what's your name?"

"I told you already! It's the Doctor!" the…Doctor said, still pressing the device to his temple.

"…Okay, and, umm…how did you get here?"

"Good question. I've been trying to figure that one out. I don't know where on Earth I am, but it's definitely Earth. I can't think of any point in Earth's timeline that would have a murderous tree farm, but I might be wrong, so I really could be anywhen. By the way, do you know what year it is?" he said, ending his highly jumbled speech with a glance at Hagrid, who had remained completely speechless this entire time."

"Oh, ah…it's 2001, I think," Hagrid said, a little taken aback by the Doctor's question. "But shouldn't yeh know what year it is by yerself?"

"I told you! I don't know when I am! I really can't tell just judging by your house. Well, maybe I could…well, I almost certainly could have…well, maybe I did…no matter, now I have an exact year!" He smiled again. "Judging by the technology…it's definitely before levitation. Pre-2056."

"Actually sir," Hermione said quietly, "Levitation is possible."

The Doctor looked at her strangely. "You said it was 2001," as though this cleared it up.

"Do you know anything about Hogwarts?" she said. The Doctor bit his lip.

"I probably should, but there's something blocking my memory- that's what this is for," and he gestured towards his 'screwdriver'.

"So you know all about magic then?" Hermione said.

To everyone's surprise, the Doctor scoffed. "Magic is impossible, kids."

"But…we saw you do magic! At the tree!" Ron burst out, finally speaking. The Doctor glanced at him.

"What, you mean that thing with the branch? That wasn't magic- that was an electric pulse magnified to the strength necessary to paralyze all plant life indigenous to Earth."

"How do you explain the living tree, then?" Harry asked skeptically. He wasn't convinced that the Doctor's electric pulse was explanation enough.

"Simple. A group of well-meaning scientists were experimenting with gene mutation. They injected some chemicals- probably caffeine- directly into the tree's DNA, before it even became a seed. The genetic strands had to mutate to accommodate the new chemical's presence, and so you get the violent tree."

"Well then, 'Doctor', explain this," Harry said. He pulled out his wand and pointed to one of Hagrid's tea cups. "_Wingardium Leviosa,_" he said, and the cup flew into the air.

The Doctor was instantly at his side as he snatched the wand of Harry's hand. "Hey!" Harry said indignantly. The Doctor ignored him as he examined the wand with one hand. (The other was still holding the screwdriver against his head.)

"How did you get this?" the Doctor said. "You reversed the cup's polarity with…this."

"That's what we were trying to tell you, Doctor!" Hermione said earnestly. "Magic is real- that's Harry's wand. He's a wizard. So is Ron here, and I'm a witch."

The Doctor shook his head at her. "This isn't a wand. This is a telepathic molecular modifier. There was only one…group of people who ever could have made this, and they're all dead now." He looked up and glared at Harry. "I'm asking you again- _where did you get this?_"

Harry was not convinced by any of the Doctor's explanations. "Look, Barty Crouch, Doctor, or whoever you are-"

Suddenly, the Doctor turned from Harry as he slowly pulled the screwdriver away from his head. "Sweet Rassilon," he murmured, sitting down heavily on the bed. He was staring blankly at something on the floor. "I thought she was just being unusually quiet…" he whispered. "But…"

He looked up at the others. "She's gone. The TARDIS…she's gone."

**A/N I tried, I really did, but Barty Crouch just _had_ to appear. But I've actually made it work into my entire plot without it being totally ridiculous! :D Reviews are welcome, expect an update in 3-5 days ;)**


	3. Chapter 3

**Disclaimer: No matter how many times I wish on a star, (are you listening, Disney?) I still don't own Doctor Who or Harry Potter.**

CHAPTER THREE

Gone.

Gone gone gone.

The vacant space where the TARDIS should have been felt like a massive black hole in his head, sucking in all the happiness he had left.

What had he said, just minutes ago? _At least the TARDIS was always going to stick around. _Another lie. Everyone he met, anything his life touched… everything was ripped away. Even the one thing he thought was his only constant.

His mind felt so…empty. So abandoned. So… alone.

The Doctor let his numb fingers drop the sonic screwdriver to the floor. He dimly noticed that the black-haired boy…Harry, that was his name…waved his hand in front of his unresponsive eyes. The roaring darkness that enveloped his mind would not let him register any kind of activity.

His time sense felt skewed. He could barely make out the rotation of the Earth beneath his feet. He felt…blind. He had never felt so still before.

Harry had left with a strange look on his face. The four people were conversing at the table, occasionally giving him worried glances. Still he could not will himself to snap back to the present. The Song in his head was gone. He couldn't hear her singing anymore. Just darkness.

He prodded the corners of his mind, trying to feel the connection with his ship. No matter where he looked, he was met with silence.

_Where are you?_ He whispered in his head. No comforting hum came to reassure him. Just a great big hole where the TARDIS should have been.

Still wandering through his own mind, searching for something he knew was not there, the Doctor managed to find something that picked his interest ever so slightly- there was a small gap in his memory, only a few seconds long, where there was absolutely nothing. Something had wiped a tiny portion of his life completely clean.

Desperate to fill the emptiness plaguing his head, the Doctor dove into the blank space. Instantly, a shrieking laughter erupted in his mind, driving through his brain with as much grace as a rusty saw. The Doctor instinctively pressed his hands against his head as the cackling changed into a painfully harsh voice that screamed in his head.

_Doctor! So good to meet you again!_

The Doctor screwed his eyes shut as the…thing from the Horse-head Nebula attacked his mind again. _Get out! _

_Ah, Doctor, still haven't remembered your manners, have you?_

_Yeah, funny thing is, I usually don't feel very friendly towards someone trying to rip my mind apart!_

_Rip your mind apart? You could call it that. Really, I was hoping for a much more technical explanation from you._

_Mmm-hmm. How about I get back to you about that? _

The Doctor ground his teeth together as the being slashed at him again. _Are you quite through?_

_Not until I get what I want from you, Doctor. _The Doctor could feel his memories being forcibly opened. Faces and names from centuries past flashed in front of his eyes.

_What you WANT from me? Why couldn't you get it when we were at the nebula? Why did you have to kill my TARDIS before coming back? _The Doctor's voice rose in volume until he was shouting.

_You knew that was me? My, aren't you a clever boy! _The being's patronizing voice felt like ice in the Doctor's mind.

_Alien being breaks through my TARDIS's defenses? Possesses me and tells me I'll never escape? TARDIS dies five minutes later? It really wasn't that hard to make the connection._

_I needed you here, Doctor. In my own universe. I required so much… energy to contact you in your universe. The connection is so much stronger here!_

_What do you want? _The Doctor said in disgust.

_You know what I want. And eventually…you WILL give it to me. I know you, Doctor- never forget that! _

With a gasp, the Doctor's eyes flew open again. The TARDIS was still gone. The being in his mind had taken her and hidden her far, far away. Somewhere where it would be impossible to find her again. But the mist surrounding the Doctor's mind seemed to have cleared, and he suddenly remembered where he was and who he was with.

Blinking, the Doctor rose to his feet and tried to register what was going on. The boy with glasses- Harry, right- had his hands pressed against his head. The girl was sitting next to him, looking astonished and a little afraid. The gigantic man was glancing back and forth between Harry and the Doctor suspiciously. The boy with red hair had stood and was pointing his telepathic molecular modifier at the Doctor.

"Who are you?" he said dangerously.

"I- what?"

"Tell us! Who are you?" he yelled.

"What do you mean? I told you- I'm the Doctor!"

The boy held the 'wand' threateningly close to the Doctor's face. "You broke into Hogwarts. Got past all the defenses like they were nothing. I'm going to ask again- _who are you?_"

"Ron-" the girl started to say, but the boy (Ron, he assumed) cut her off with a quick "I'm a little busy, Hermione."

"All right, I already told you my name- it's the Doctor." The Doctor looked at Harry, who was still clutching his head. "And…what's wrong with Harry?"

Ron seemed a little startled by the change in subject. "Don't you remember? You just sat down and stared off into space over there for a while, and then you both grabbed your heads like you were possessed!"

"Harry did too?" the Doctor said, surprised. He looked over at the black-haired boy. Clearly, the being had left its mark on Harry's mind. His eyes were still squeezed shut and he was wearing a grimace of pain on his face.

The Doctor walked closer to Harry. "Harry?" he said quietly. "Harry, can you hear me?" Harry didn't respond. "Harry, it's okay now, just open your eyes."

Harry still didn't move. The Doctor frowned. "Harry, can you hear someone? Someone else not in here?"

The girl (Hermione, he remembered) spoke up. "Sometimes…sometimes Harry does this. Usually its when…well, it's when…_Voldemort_ is angry. Very angry."

"Who's Voldemort?"

All three people got unnaturally quiet, like they were holding their breath. The tall man spoke up.

"What do yeh mean, who's…You-Know-Who?" he said. "Yer old enough to have been around for the last war."

"War?" the Doctor said with a little confusion. All three people stared at him incredulously.

"So…you really aren't a wizard?" Hermione said in a small voice.

"That's what I've been trying to tell you! _Magic is impossible_! I don't use magic!"

"I don't know," Ron said. "You look an awful lot like Barty Crouch Jr. Maybe he just got his memory erased."

"Ron, Barty Crouch got his _soul_ erased!" Hermione said with exasperation. "That's not something you can ever recover from!"

"_Who _got his soul erased?" The Doctor said worriedly.

"You did," Ron said, but Hermione shushed him.

"Are there any…blank spots in your memory, Mr...Doctor?" she said.

"Um…not really, no. I can remember pretty much everything since I was one hun- since I was one." The Doctor felt that maybe now was not the right time to let everyone know he was an alien. Somehow he didn't think that would go over very well.

"Since you were _one?_" Ron said. "Photographic memory," the Doctor explained.

"So...there's nothing you don't remember? No time when you were…I don't know, maybe…a Death Eater?" Hermione said tentatively.

"Nope," the Doctor said, popping the 'p' at the end.

"And you think magic is impossible? No way in the world it could exist?"

"No way in all of time or space. I know that for a fact."

Hermione seemed a little confused at this, but she held her ground. "Can I see your left arm?"

"My _arm?_"

"Yes, I want to see if you have a…you know. A…dark mark."

The Doctor looked confused, but he pulled off his coat and rolled up his left sleeve. Except for a few scratches, it was bare.

"Okay, I guess that proves it- you can't get a dark mark taken off," Hermione said. "You really aren't Barty Crouch Jr."

"You know, I did tell you several times that I wasn't. My _name _is the Doctor."

"So what do you think happened?" Ron asked Hermione. "He's a Muggle- he couldn't have gotten in without a wizard's help."

"Excuse me, what did you call me?"

"A muggle. Means non-magic folk," the tall man said.

"Oh. Also, remind me, your name is…?" he said. "Hagrid," the tall man replied. Hagrid. Interesting Earth name. He hadn't met many of those in 2001.

Suddenly, Harry yelled and his eyes flew open. He was panting hard. The Doctor was at his side again faster than he could blink.

"Harry, can you hear me?" he asked again. This time Harry nodded.

"Harry, I want you to look in my eyes. Come on…that's it…good boy. Okay, let's take a look here, shall we?" The Doctor pulled out his sonic screwdriver. It was already at 63D, so he could scan Harry's brain for another presence.

"Oi! Look! There's his wand!" Ron said. The Doctor shook his head. "It's _not_ a wand, it's a screwdriver. A sonic screwdriver." He was taking a gamble with that. Something about this universe felt…wrong. And until he figured out what it was, he wanted to keep them all believing he was a human.

Harry looked at the metal device in the Doctor's hand. "I'm fine, Doctor, I just need to-"

"Don't you pull that stunt with me, I've used it myself quite a lot," the Doctor said firmly. "This is only going to take a second." He pressed the screwdriver against Harry's head and pressed the button down for half a minute.

The Doctor frowned. The screwdriver was picking up…three presences in Harry's mind. He could account for two of them- the being that had possessed him, and Harry's own mind. But…what was the third?

Suddenly, the door flew open and two people strode in Hagrid's hut. One was very old, with a white beard rippling all the way to his waist. He was wearing silvery robes and half-moon shaped glasses. The other man was tall, with greasy black hair that hung at his shoulders. He had a hooked nose and dark eyes that seemed completely black.

When he saw the Doctor, the second man started abruptly. "_Barty Crouch Jr.?"_ he whispered sharply. "That's…impossible!"

"Who is this Barty Crouch you lot keep going on about?" the Doctor asked, mystified.

"We received your message just a moment ago, Hagrid," the first man said. "I must say, Harry, Hedwig is an extraordinarily prompt owl."

Next to the Doctor, Harry nodded, his jaw still set tightly.

The second mane had come unnervingly close to the Doctor. The Doctor leaned back as the man stuck his large nose right into the Doctor's face.

"Um…do you mind?" the Doctor said with a little annoyance as the man drew in even closer.

"Incredible," the man said. "The resemblance is uncanny."

"To this Barty fellow, I assume," the Doctor said. "Now could you please back up just a smidge?"

"Albus," the man said. "This is, without a doubt, the work of Dark Magic."

"Now, Severus, we cannot even be sure that he really is Barty. After all, Barty did get his soul removed."

"Will someone please tell me who Barty is?" the Doctor said. After a moment of silence, he continued. "No? No explanation at all? Okay, then…"

"Excuse me, Professor Snape," Hermione said. "I checked the Doctor's arm, and it, um, didn't have a Dark Mark."

"Checked _whose_ arm, Miss Granger?" Snape replied in a nasty voice.

"The Doctor's arm," the Doctor said. "I'm the Doctor. Hello!" he said cheerfully.

Snape sneered at him. "You call yourself…the Doctor."

"Yup! That's my name!"

Snape scoffed. "Then how do you explain your incredibly resemblance with a certain Death Eater?"

"A Death Eater?" the Doctor asked, puzzled. "What's that?"

"Sir, the Doctor doesn't think magic exists. He's a muggle," Hermione said.

"Explain your presence here, then, 'Doctor'! How did you break into Hogwarts?"

"I really have no idea whatsoever. Well…maybe a few. Well…maybe a little more than a few…well, maybe a lot…"

"Answer the question!" Snape growled, pulling out his wand and pointing it threateningly at the Doctor's chest.

"You have one too? That's impossible! Where did you get this?" the Doctor stammered. He wished the TARDIS was still around, so that some other person would understand his confusion. How the heck did the humans have so much Time Lord technology?

"Answer me," Snape said.

"I told you- _I don't know!_ Now will you answer _my _question?"

Snape pressed his lips together, never letting his wand waver from its position over the Doctor's left heart. "Albus, I do not believe he is going to answer us without some…different methods."

The old man turned from the whispered conversation he had been having with Harry. "Are you proposing that we use Legilimency on him?" he asked.

"It appears we have to."

The man gave Harry, Ron, and Hermione a significant glance. "Very well," he said after a moment's consideration. "Now if you four could follow me outside…" The five left the hut, leaving Snape and the Doctor alone together.

The moment the others were gone, Snape shoved the Doctor into a chair. The Doctor opened his mouth to protest, but Snape muttered something under his breath and thin ropes appeared out of thin air, tying the Doctor to the seat tightly.

"Oi!" the Doctor said indignantly. He pushed against the ropes to test their strength. They restrained him easily.

Snape leered at him. "This is your last chance, Barty. Tell me how you are alive and how you got into Hogwarts or I'll find out myself."

"I'm not Barty Crouch!" the Doctor said. "I've really told you everything I know!"

Snape scowled. "Then prepare to have your mind opened, Barty." The Doctor's eyes widened as understanding set in. Snape wanted to break into his memories! He instantly threw up his basic mental shields. Snape was only a human…he wouldn't be able to cause much damage…wouldn't he?

Snape twitched his want, and suddenly the Doctor's mind was attacked by a huge force- so much stronger than what he had expected!

The mind probe smashed the Doctor's shields easily. The Doctor put up more powerful ones as fast as he could. The mental force tore these apart just as fast.

Desperately, the Doctor tried one more time to fend the probe off, but he had been caught off his guard for once and was now suffering the consequences as his last shields were toppled and Snape gained access to his mind.

Instantly, images of Donna appeared, followed by Martha, then Rose. There they were, all three of them in the TARDIS as they pulled the Earth back into time…further back, him and Martha and the Master aboard the Valiant…Canary Warf flashed in front of him now, as Rose fell towards the Void…the night he had regenerated into his tenth incarnation…meeting Rose for the first time…and then his life before that.

The Doctor gasped as he was pulled back further. He could sense something as his memories reawakened- something was coursing through him, getting stronger the wider Snape opened his mind…

Traveling to Earth as Nine, all on his own…before that, regenerating aboard the TARDIS…hurtling through the Vortex as time and space was locked behind him…and then…

The memories stopped briefly as Snape hovered over the last locked part of the Doctor's past. It was surrounded by the Doctor's strongest shields, the only things keeping him sane.

Behind the shields, the Time War prowled, locked out of the Doctor's memory.

Snape hesitated, then flung open the Time War.

_NO! _the Doctor screamed mentally. _NO! I CAN'T DO IT AGAIN!_

As the fiery memories flooded his head, the Doctor could feel raw energy pouring through his body. Snape was ripping open his _soul_, and he was about to see a Time Lord unleashed.

The unstoppable memories coursed between the Doctor and Snape. The Doctor could feel his eyes burn. The Time Vortex that swirled within him was now blazing golden in his eyes, and judging by the look on Snape's face, he was horrified at the powerful creature the Doctor had become.

As the hidden energy inside his mind was opened, the Doctor found that Snape's mind had faltered. Pressing his advantage, he grabbed Snape with a psychic hand.

_I think you've seen enough, _he mentally hissed.

The Time War was exploding inside him. The Fall of Arcadia. Watching his friends, his _children_, die in front of him. And then…triggering the final weapon to end the war. Watching alone from above as his entire species burned on Gallifrey below.

Anger, despair, and a crushing guilt filled him. Even though he kept his eyes wide open, tears were pouring down his face. Snape was trembling, his black eyes terrified.

_Get out of my head,_ the Doctor said with as much force as he could muster. Finally, Snape nodded and withdrew into his own head.

The memories went away as the Doctor firmly locked them away again the moment Snape was gone. Closing his eyes, the Doctor replaced his mental shields, guarding his mind much closer after Snape's psychic attack.

"I should kill you now," Snape murmured, pointing a shaky wand at the Doctor.

"You wouldn't do that. You've seen what happens when I die, and aren't you scared enough right now?" the Doctor said heavily.

For a moment, Snape wavered, then lowered his wand.

"You are not to tell a word of this to anyone," the Doctor said darkly. "Now if you'd kindly untie me?" The ropes fell away just as quickly as they had appeared. He stood up and glared at Snape.

"Come along, Snape. They're waiting for us outside."

**A/N I'm not sure if I wrote this scene very well, so review and tell me what you thought! :D**


	4. Chapter 4

**A/N Your reviews are making me happy :D Thank you, everybody!**

**Disclaimer: In the three days since I last posted, I still do not own Doctor Who or Harry Potter. **

CHAPTER FOUR

Harry, Ron, Hermione, and Dumbledore were standing in a circle just outside Hagrid's hut. Hagrid had left for the school building, muttering something about needing more flesh-eating slug repellent. Harry had been telling them all what had happened. The Doctor had shown up out of nowhere, and was telling them that magic wasn't real. Then he had had some sort of attack, and no matter how hard he had tried, Harry couldn't get him to snap out of it. He had sent Hedwig to Dumbledore after that, and then…

The voice started speaking in his head.

"What do you mean, a voice?" Hermione had said. "It wasn't…You-Know-Who, was it?"

It hadn't been Voldemort. This voice was more mocking, more triumphant. It sounded like it had already…won something, and was on the verge of winning something else.

"Harry…you don't think You-Know-Who's got some other overlord on his side, do you?" Ron had asked.

Harry desperately hoped not. This voice had made him feel so tiny, like the voice knew everything and was merely playing with him. Voldemort, at least, he could see. This felt like something different all together.

"What did the voice say, Harry?" Dumbledore had said. "What did it want?"

Harry couldn't make sense of it. What he had heard sounded like just one half of a conversation, as though the voice hadn't been speaking to him directly. Like Harry had been eavesdropping on something.

What had the voice said?

_So good to meet you again!_

_Rip your mind apart? You could call it that. Really, I was hoping for a much more technical explanation from you._

_You knew that was me? My, aren't you a clever boy!_

_I needed you here. In my own universe. I required so much… energy to contact you in your universe. The connection is so much stronger here!_

There had been more, but those had been the clearest words. When Harry had told Dumbledore what the voice had said, he had looked worried. And…possibly…confused. What on earth could confuse Dumbledore? He was the smartest man in the world!

There was silence after that. Each person was wrapped up in their own thoughts. Harry had a massive headache. The voice still seemed to echo in his head. Then the door had opened.

When Snape and the Doctor came out of Hagrid's hut, Harry had not at all expected Snape to be the one that looked traumatized.

Harry stared at the two of them. The Doctor had a forced smile on his face, but his eyes…they looked so angry and…dark. Snape was another matter. He was trying to look impassive, but his eyes told another story as well. The terror flickering in them was barely veiled.

"Well, Snape? Can we trust this man?" Dumbledore said.

Snape swallowed, then answered. "He is not Barty Crouch Jr. He…just happens to look like him. He is a muggle and did not break into Hogwarts intentionally. He stepped into an enchanted phone box by accident and was brought here through…someone else's magic."

Throughout all this, the Doctor didn't make a sound. He kept glancing up at the Whomping Willow's hill. Harry looked closely at him and…was it just his imagination, or had his eyes flickered gold when the phone box was mentioned?

"Well, that is interesting. Intriguing, one might say. This certainly gives us food for thought about what our enemy is capable of," Dumbledore said, with a ghost of a smile on his face.

"Mmm…wait, did you said enemy?" the Doctor said, suddenly taking an interest in the conversation.

"Ah, yes, you don't know about Voldemort," Dumbledore said kindly.

It was as though a cold wind had swept through the valley, because Hermione and Ron instinctively shuddered.

"Voldemort?" the Doctor laughed, seemingly unaffected by the word. "What kind of a name is that?"

"Just as there are good wizards in this world, Doctor," Dumbledore said, "There are evil ones as well. Voldemort is our greatest enemy, and is currently waging a war against every witch, wizard, and muggle who strives to uphold the good in the world."

"Still, how bad can he be with a name like 'Voldemort'?" the Doctor said, still grinning with amusement. "I mean, 'Voldemort' sounds _way_ too much like 'Moldy Wart'. If I was going to be an evil overlord, I would choose a better name. Like…hmm…I don't know." The Doctor frowned, pondering over the best overlord names.

Everyone except Dumbledore seemed shocked by the Doctor's nonchalance attitude when it came to the most feared wizard of all time.

"No matter how silly his name is, he is still a force to be reckoned with, Doctor. I suppose you have been hearing about all the disappearances and unexplainable deaths recently?" Dumbledore said.

"Er…" For the first time, the Doctor seemed stumped. "I…uh…that depends…what year is it?"

"Oh, come off it!" Ron said loudly. "You can't seriously _not know_ what year it is!"

"Yes, Doctor, explain why you don't know what year it is," Snape said with a twisted smile.

"Really bad hangover," the Doctor said sarcastically, stepping closer to Snape. "You want to make something of that, mate?" He gave Snape a dangerous look, and for some reason, Snape actually did stop talking.

"Excuse me, Mr. Doctor," Hermione said in a small voice. The Doctor stared at Snape for a moment longer, then turned to her. "Yes?"

"It's 1996."

"_Thank you_," the Doctor said. "Okay, 1996…mysterious disappearances…unexplainable deaths…" the Doctor closed his eyes and frowned. "Ah…no. Not ringing any bells. At least…not where I'm from…" A strange looked passed over the Doctor's face, but it disappeared in an instant.

"Right then!" he said, clapping his hands together. "You were saying, Mr.…?" he looked at Dumbledore expectantly.

"My name is Professor Dumbledore," he said.

"A professor, all right then. So…disappearances, deaths, and Moldy Wart are connected."

"Voldemort, yes. He and his Death Eaters have been roaming the world, killing muggles for sport, and any witch or wizard that get in their way."

"Oh, well, that's not very nice, is it?"

"No," Dumbledore chuckled. "No, it's not nice at all. You are lucky to have escaped their notice. However, here at Hogwarts, you should be safe. It has been shielded by the best enchantments that, until now, at least, have never been breached."

"So…this 'Hogwarts', then, what is it?" the Doctor asked.

"It is a school for young witches and wizards. We teach them how to control and channel their magical abilities for good."

"A school!" the Doctor said. "Oh, well, that makes a lot more sense than a murderous tree farm! Still," he said hastily, "you might want to take that tree out. I've got a feeling that it's not exactly…innocent. I mean, tampering with anything's genetic code is always a bad idea, but this is an exceptionally _bad_ case of genetic mutation, with another satchel of _bad_ on top of that."

"Nothing has been done to the tree's genetic code, Doctor, I can assure you. That is a magical tree, and it has our protection."

"I wouldn't be too sure about that," the Doctor muttered under his breath, but let the matter drop. "Right, I'd better be off, then," the Doctor said. "This really…isn't the right place for me to be, and right now-"

"Wait a moment, 'Doctor'," Snape said. "You have still broken into Hogwarts, and if we let you go, you might tell others about us. I think it would be wise, Headmaster, if we kept the Doctor here."

"You think I'd go out and tell people that magic is real and there are wizards living right under their noses?" the Doctor said incredulously. "Who would believe me? Well…then again, if UNIT and Torchwood are still out there, they might…never mind."

"You see, Headmaster?" Snape said. "This man could still possibly be dangerous. I say we keep him here until…we see fit to release him."

"As much as I dislike the idea of forced confinement within Hogwart's grounds," Dumbledore said, "you may be right, Severus. For the time being, Doctor, I would request that you do not leave the grounds."

The Doctor looked shocked. "But somebody killed my…" he started, before trailing off into silence. "I…never mind, again."

"You will have free rein of the building and surrounding areas, Doctor, but please don't…wander off."

The Doctor sighed, his gaze drifting off to the Whomping Willow again. "I don't have a choice, then?" he said quietly.

"I'm afraid not," Snape said, but the twisted glee written in his eyes said he was not sorry at all.

"Well…"

"I have an idea," Harry suddenly said. He really didn't like the malice shining in Snape's eyes every time he looked at the Doctor. "Why don't me, Ron, and Hermione show him around, since he's going to be here for a while?"

The Doctor's mood spun around 180 degrees. "That's a brilliant idea!" he said cheerfully. "I love teenagers. Always having clever ideas, coming up with the best solutions." He had a wide smile on his face, and his eyes seemed to sparkle with excitement.

"Ah…okay then," Harry said, smiling as well, a little incredulously.

"All right, let's go," the Doctor said, striding away. "Come on, kids!" he walked away in long strides. As the four of them walked away, Harry could hear Dumbledore whisper to Snape-

"Who is he, Severus?"

The answer made Harry uneasy.

"Someone we should never make our enemy."

…

They walked all the way to the edge of the lake, the Doctor jabbering on non-stop.

"I've heard that there are some mutant trees that scientists are working on. They've been injecting their cells with all kinds of chemicals, trying to see what comes up. I've seen plant cells get shot with peroxide, distilled alcohol, liquidized mercury…they even tried combining a banana tree's cells with pineapple juice! It was ridiculous! Made the bananas taste far too much like citrus. Bananas should _not_ taste like citrus. Bananas should be…banana-y. Is that a word? Banana-y? I suppose anything can be a word, as long as there's someone using it and it means something. I could say that 'Raxophalipatorious' is a word. It is...could be a planet in the Andromeda galaxy where the Slyveen live. Would that make it a word? I suppose to the Slyveen it's a word. It's the name of their planet, after all! I think they call 'earth' Sol 3, because it's the third planet from the star Sol. Humans should be called Solians, really. It makes much more sense. 'Earth' really has no connotation with the planet's galactic coordinates whatsoever! And the word 'human'. It doesn't make sense! Why do you all…we call ourselves 'humans' in the first place? Someone just made up that word one day. You…_we_ even have the Mars issue worked out- if someone's from Mars, then we call them Martians. If we're from Earth, shouldn't we be Earthians? No, wait, this planet is Sol 3. We're Solians."

Harry really wasn't taking in a word that the Doctor was saying. It all seemed like background noise to him. He still had a pounding headache, and his scar was tingling. Did that have something to do with the voice invading his head?

Ron seemed to be staring off into space…or, more likely, at the group of pretty young Ravenclaws that had just assembled at the other edge of the lake. Hermione, however, seemed to be genuinely interested in what the Doctor had to say.

"So…what you're saying is…there are aliens that call us Solians?" she said.

"What…? Oh, um…no, there's…er, no such thing as aliens," the Doctor said quickly. "I was just…rambling. I have a tendency to just…talk and talk and talk. I've got quite a gob, obviously."

Hermione nodded slowly. "But…_you_ think we should be called Solians?"

"Well…yeah, that's what I grew up thinking…"

"You did?"

"Oh…not, er, literally. I've just always thought it would be a good name for…us."

"You said something about galactic coordinates. I've never heard of them."

That perked Harry's attention. _Hermione hadn't heard of something?_

"Oh, well, it's really simple really. Just imagine that you have a map of the universe, and the coordinates of your planet dictate what your planet should be called."

"But…having a map of the universe would be impossible. It doesn't have a start or an end."

"Well, you'd have to draw it in five dimensions, to account for all galaxies at every point in time, because sometimes…sometimes planets and galaxies get erased from time and space, but they were there at one point, they just…only exist on a few people's timelines. Plus, time can get…wibbly-wobbly. A map of the universe would have to be drawn outside of time, because then the cartographers would do it without a temporal standpoint."

"Draw a map in five dimensions…" Hermione's voice trailed off. "That's not possible."

"Not in a three dimensional world, you're right. We wouldn't be able to point the lines in the right directions, because the directions wouldn't exist for us."

Hermione shook her head. "Then how do galactic coordinates exist?"

"Apparently, someone skipped out of time for a while and plotted the universe."

"That's impossible as well."

"Well, if you spend enough time in the Time Vortex…sorry, bad choice of words. If you waited in the Time Vortex, where time doesn't exist, then you could do it."

Hermione didn't answer to that. Harry frowned at the Doctor. "The Time _what?_"

"Oh…it's a…theory I've been working on."

There was a minute of awkward silence.

"So…why did you kids get out of school so early?" the Doctor said.

"We're supposed to be in Astronomy class right now, but our teacher disappeared last week, so we get a free period now," Harry said.

"Your astronomy teacher went missing?" the Doctor said, interested. "That's…that's quite a coincidence…" he fell silent.

"Why is that a coincidence?" Ron asked. He seemed to have forced his eyes away from the girls now feeding the giant squid pieces of bread.

"Oh…oh, it's nothing." The Doctor stood up. "What time does your next class start?" he asked, choosing to ignore Ron's question.

"In about five minutes," Hermione said, standing up as well. "Speaking of, we really should get going."

Harry and Ron rose. "Yeah, you're right. It was…um, nice to meet you, Doctor."

"You as well…" the Doctor said. "Very nice…yes…oh, Harry?"

"Yeah?"

"How can I get a note to Professor Dumbledore?"

"Uh…" Harry was surprised by this question. "I guess…you can borrow one of the school owls. They carry letters. They're over there, in the Owlrey." He pointed to the tall tower.

"All right. Thank you!" The Doctor sprinted away.

The three watched him run to the tower.

"This has officially become the weirdest day of my life," Ron said.

…

A few hours later, after their Potions and Transfiguration classes, Harry, Ron, and Hermione were sitting in the common room, absentmindedly trying to finish an essay for McGonagall describing the exact changes that come about when a lemur changes into a letter opener.

"So…" Ron said, finally breaking the silence. "Who else is thinking about…the Doctor?"

"I am," Harry said, putting down his quill. He really had been thinking about the entire day- his headache was all but gone, but there was still a trace where the voice had hacked into his skull.

"So am I," Hermione said. "There's something about him that seems…different from other people."

"I know what you mean. The bloke wouldn't shut up," Ron said.

"No, not like that. If you were really listening to what he was saying, it was…I don't even know how to describe it. It was like he was talking just for the sake of talking…it sounded like he was trying to…I don't know…" she stopped, embarrassed.

"What did it sound like?" Ron encouraged.

"Well…it's going to sound silly."

"If it's silly, we won't laugh," Harry said. There was something about the Doctor that had made him feel a bit uneasy as well.

"It sounded like…he was speaking because he was missing something else. Like part of him was gone, and he was making sure…'he' was still around."

"You said…'still around'. Like something had gone away."

"I don't know exactly how to describe it, but... he sounded a bit…desperate."

"Desperate? Him?" Ron said. "What would he be desperate about?"

"I don't know. The only one who would know would be Snape, I guess," Hermione said.

"Speaking of Snape," Harry said, "did you see his face when he came outside? He looked like he was about to faint, he was so scared!"

"I didn't notice," Hermione said. "But why…I mean, the Doctor isn't exactly, intimidating, is he?"

Their conversation was cut short, however, when Ginny walked up to Harry, holding a slip of paper tied with a purple ribbon in her hand.

"Hey, Harry," she said, handing him the paper. "I'm supposed to give this to you."

"Oh- thanks, Ginny," he said, taking the note from her. She stood there for a moment, awkwardly. "I'll just go then," she finally said.

"Um, yeah…yeah, okay," Harry said, finding his own voice. He looked down at the paper for a minute, before untying the ribbon and unrolling the note.

_Dear Harry,_

_I trust that your afternoon continued without any more strange interruptions. I am writing to request your presence in my office at 6:30 this evening so that we may discuss the events of this afternoon._

_~Prof. Dumbledore_

_(P.S. I enjoy Fizzing Whizzbies. Perhaps you do as well?)_

Harry stared at the note. He enjoyed Fizzing Whizzbies? Oh…no, that must be the password to Dumbledore's office.

"Hermione, what time is it?" Harry asked.

"6:25. Why?"

Harry jumped out of his chair. "I'm supposed to be in Dumbledore's office in five minutes!" he yelled, then ran out of the common room.

…

Harry burst into Dumbledore's office a few minutes later.

"I'm sorry, sir," he panted. "I just got your note…a minute ago…"

Dumbledore smiled. "That's quite all right, Harry, you are only three minutes late. Now come, have a seat." He waved his wand, and a comfortable chair appeared in front of his desk. Harry gratefully sat down.

"Now, Harry, I have asked for you to come up here to discuss the strange events that transpired today. Never before has anyone, much less a muggle, broken into Hogwarts. You spent the day with the Doctor. Tell me- what do you think of him?"

"I…" Harry thought for a moment. "Well, he definitely likes to talk."

Dumbledore smiled again. "Yes, I thought he might."

"Really, he wouldn't shut up. He kept going on about temporal divides, genetic mutations, and whatnot."

"Fascinating," Dumbledore said, more to himself than to Harry.

"Sir…" Harry hesitated. "Sir, I heard what Snape said to you as we were leaving with…the Doctor."

"Really? And what was that?"

"That…we should stay on the Doctor's good side. That we didn't want him as an enemy."

"Ah. Now there, you raise an interesting point. What did Snape see inside the Doctor's mind? He refuses to tell me, and believe me, Harry," Dumbledore lowered his glasses, giving Harry the feeling that he was being x-rayed. "Snape tells me everything."

"You think the Doctor is a wizard then?"

"No, I think he truly is a muggle, who happens to have an extraordinarily brilliant mind."

"Oh. Wait…extraordinarily brilliant?" Harry had gotten the impression that the Doctor was smart, and maybe a bit insane, but not that he was a genius.

"There is another reason I asked you up here, Harry," Dumbledore said. He lifted a piece of paper from his desk. "The Doctor sent me a note soon after he left you."

"Oh yeah, he said something about getting an owl," Harry said.

"It seems he managed to find one, because I received this note from him." Dumbledore readjusted his glasses and began to read the note.

"_Professor Dumbledore- There are two reasons why I am writing to you- first of all, I really am sorry for giving you all such a scare. I really didn't mean to break into your school. In fact, if I had it my way, I would never have come here. Secondly, Harry has recently told me that you are missing an astronomy teacher. As it so happens, I sort of have a doctorates degree in astronomy, and would be happy to apply as a new teacher-"_

"Hang on a minute," Harry said. "Isn't wizard astronomy a lot more advanced than muggle astronomy?"

Dumbledore chuckled. "That it is. But let us hear what our friend has to say on the subject." He continued to read the note:

"_Now tell Harry that I know 'wizard' astronomy is more complicated than 'muggle' astronomy-" _(Harry openly gaped at this)_ "-but I guess you could say that I'm a little more advanced in astronomy than most muggles as well. So you can tell Harry to close his mouth now- I'm not a mind reader, I just am pretty good at predicting the future."_

This of course made Harry's jaw drop even wider.

"_Thanks for taking the time to read this. Tell Harry I said hello. I really wish I could see the look on his face right now. From the Doctor." _

Dumbledore laughed lightly again as he put the note down.

Harry couldn't make out a complete sentence. "I…that's…what…I don't…how…?" he stuttered.

"I think that the Doctor would have been quite pleased to see your expression, Harry."

"But…how did he know what I was going to say?" Harry finally said.

"I believe he just has some very well developed powers of prediction. He guessed that I would want to talk to you, and that when I told you he was applying for the post of Astronomy teacher, you would protest. Therefore he developed his arguments ahead of time."

"That's…I mean…wow."

Dumbledore smiled. "He is right, you know. We do need a new astronomy teacher, and I believe he would fit the job perfectly. What do you think? Can I trust him not to murder the students in their sleep?"

"I…yeah, I guess…"

"Very well," Dumbledore said. "I will send him a note saying his request has been accepted. And now…" Dumbledore glanced at his watch. "I believe it is time for you to head back to your common room. You have quite a lot of homework, I presume?"

Harry rolled his eyes. "Don't remind me. Okay then. Thanks, Professor."

He stood up and left the office, his mind reeling.

**A/N Okay, it was kind of boring. :P But now you know that the Doctor is going to be teaching Astronomy to all these little witches and wizards! It's going to be…interesting… ;) REVIEW!**


	5. Chapter 5

**A/N Oh my word, people. Your reviews are making me giggle like a lunatic! In a good way, of course. ;) Keep 'em coming, folks! :D**

**Dark Dark Angel- I felt the same way! That's why I decided to finally write my own. :)**

**Disclaimer: No Who. No Potter. Nope. Nada. Goose eggs.**

CHAPTER FIVE

The Doctor had just sent a note to Dumbledore. The owls in the Owlrey had not been exactly…inviting. Several had pecked at his fingers and refused to send the note before he finally found a scrawny owl hiding behind the others that would take the message from him. He supposed it was his 'muggle' aura that was putting them off. Or maybe they could somehow sense that he wasn't supposed to be in this universe.

The Doctor climbed down the winding steps. There were hardly any students out on the grounds, but every time he passed someone, they did a double take. Apparently, there weren't many adults wandering around that weren't teachers.

Over on the grassy hillside, above the vicious tree, the Doctor could see the blue speck that was the TARDIS. Of course, that was where he was headed now. He remembered the last time he had accidentally crashed into a parallel universe with Mickey and Rose- maybe there was still a power cell somewhere, clinging to life just like before…

It was a good thing there weren't any students outside, because the Doctor would have run right into quite a lot of them on his way to the TARDIS. He made his way around the lake, carefully skirted around the living tree, and climbed up the steep grassy slope where the TARDIS was laying on her side.

Smoke was still curling from the open doors. The Doctor hesitated for a moment, tentatively trying to reach the TARDIS's mind now that he was closer. Again, his hearts sank when there was no reply. Kneeling down, he crawled sideways into the TARDIS.

The entire room was on its side, so he was walking on the coral patterned wall. The main console was running sideways from one end of the room to the 'ceiling', which was quite a ways away. The Doctor walked to the computer, which was dangling down, still attached by a few strong wires.

"Computer…scan for life…?" he said quietly, hoping for some kind of response. There was nothing. He sighed dejectedly. Nothing he could do would get any answer.

His eyes flickered to the grating covering the millions of wires and energy cells running under the control center. Last time he had been flung into a parallel universe with Mickey and Rose, there had been one little energy cell clinging to life and normal existence. He had powered it up and they had been just fine. Maybe…just maybe there was another one…

The Doctor pulled off the metal grating sheets, desperately scanning for the smallest glow of light that could send him back home. At one point he thought he saw a tiny flickering light tucked away in the corner, and his spirit had soared as hope came again, that maybe he could go back to his own universe…

The 'light' turned out to be the reflection of his sonic screwdriver on a mirror-like memory cell.

As his hearts plummeted, the Doctor shook his head and slumped down heavily onto the floor. There was nothing. Not the slightest trace of life anywhere. His TARDIS had been killed. The last TARDIS in all of time and space…now extinct. He truly was completely alone now.

The Doctor wasn't supposed to cry. He was supposed to be unshakable. He was supposed to be the Oncoming Storm- enemies were supposed to tremble at the mere mention of his name. But right now the rules of the universe were broken, and for once, the Doctor felt completely overwhelmed. After all, what was a Time Lord without his time machine?

At the foot of his dead TARDIS's console, the Doctor cried. He tried at first to hold back his emotions, but they were breaking through like water bursting a dam. It suddenly became too much, to have this final bit of his home ripped mercilessly away. The tears started slowly and quickly began to flow freely. His dam was breaking as the tide of suppressed emotions was finally let loose.

He brought his head to his knees, curling into a ball as sobs shook his whole body. One hand subconsciously reached out to the TARDIS, stroking it as though this would somehow bring her back.

_Where are you? _He whispered into the darkness of his mind. _I need you!_

But for once, the TARDIS was not there for him. She had left him…just like all the others.

Gradually, the Doctor tried to get a hold on himself again. Gasping with final ragged dry sobs, he managed to pull himself together. Pushing himself up from the floor with trembling arms, he wiped the last tears from his cheeks. Taking deep breaths, he finally noticed a strange fluttering sound. Looking at the sideways door through bleary eyes, he had to blink a couple times to make sure he was really seeing what he thought he was.

A large white owl with tan-tipped feathers was flying back and forth from inside the TARDIS and back out again. A small note was tied to its leg. As it flew back inside, the Doctor saw that its eyes were unnaturally wide and surprised, as though it couldn't believe what it was seeing.

The expression was so similar to most of his companion's when they first saw the bigger-on-the-inside TARDIS that the Doctor nearly laughed out loud. Pulling himself into a standing position, he walked across the 'floor' (actually the wall) and walked outside so that the owl could give him the note.

The owl was perched on top of the TARDIS, not looking down as though it was trying to pretend it hadn't seen the inside. Amused, the Doctor reached down and tried to untie the note. The owl pecked at his hand viciously. The Doctor sighed in exasperation.

"Not you too!" he muttered. "Look- I know I'm a muddle puddle, or whatever you call a 'non-magic' person, but I'm the Doctor and that's for me!" he said indignantly. The owl gave him a suspicious look, but eventually held out its leg for the Doctor to untie the letter.

"_Thank you_," he said. "Now go back to wherever you owls go when you're not delivering notes!" He made a shooing motion with his hand, and the owl flew away with an indignant huff.

The Doctor rolled his eyes. Crazy owls. He unfolded the scrap of paper and read it in an instant.

_Dear Doctor,_

_Your application as Hogwart's School of Witchcraft and Wizardry's new Astronomy teacher has been accepted. You have one day to prepare lessons for the fifth, sixth, and seventh years. Your private room is located on the seventh story, behind the second door to the left of the Astronomy tower. The classroom (with your office attached) is at the top of the tower, first door to the right. I thank you for your application and wish you luck!_

_~Professor Dumbledore_

_(P.S. Harry's expression was rather enjoyable. You have most definitely left an impression on Mr. Potter!)_

The Doctor smiled wryly. So Harry had gotten to hear the note after all. He envied Dumbledore- the look on his face must have been priceless.

And he was going to be the Astronomy teacher. He had mainly applied just to keep himself occupied, since he was obviously not going anywhere soon, not with that Snape fellow breathing down his neck. Well, those kids certainly were going to get lessons- very, very interesting lessons.

He squinted up at the sun. It was setting quickly, the sky turning purple and orange as Sol 3 sank beneath the horizon. It must be…6:37 at least. Most likely he had missed the dinner they were serving; no matter, he wasn't exactly hungry anyway. He probably should get started on those lessons, however…

Considerably more cheerful than he had been a few minutes ago, the Doctor tucked the note into his pocket and set off back down the hill, determined not to look back at the TARDIS once.

…

When the Doctor walked into the main building, the first things he noticed where the ghosts.

"Hello, who might you be?" said one of the transparent beings floating a few feet off the floor. The Doctor blinked in absolute surprise. Ghosts? Impossible. He pulled his glasses out of his pocket and put them on, trying to make sense of what he was seeing.

"Excuse me, sir, but are you quite sure you are supposed to be here…?" the ghost said.

"Yes, positive, have to be, of course I am…" the Doctor said absentmindedly. He really should resist. He _really _shouldn't scan the 'ghost'. But…oh, he _really_ wanted to know what it was…

Before he could stop himself, the Doctor had whipped out his sonic screwdriver and flipped it to setting 98Q (species confirmation). He pressed down on the button and scanned the ghost.

"I say sir, what _are_ you doing?"

"Incredible!" the Doctor finally said. "This is the most advanced form of a temporal echo that I've ever seen! And believe me, that is _saying_ something."

The ghost seemed flustered. "I am _not_ a…temporal whatnot. I am Sir Nicolas de Mimsy…"

"I'm sure you were, at one point," the Doctor said, still scanning Sir Nicolas with the screwdriver. "Still- _how_ long has your impression stayed around?"

"I became a ghost 206 years ago, if that is what you mean."

"_206 years? _That's…that's…what kind of technology are you lot _using_? That is… physically impossible to hold an impression that long. You should have died as an echo after a week at the most. But…here you are, with a physical appearance, even! That is _amazing!_"

Sir Nicolas blinked rapidly. "I don't believe I followed even half of what you were saying, Mr.…?"

The Doctor smiled. "I'm the Doctor, nice to meet you. I'm a…what did you call them? Oh, yes, I'm a muggle, and I'm the new Astronomy teacher."

Flashing a bewildered Sir Nicolas a grin, the Doctor spun on his heel and walked away to where he thought the Astronomy tower ought to be.

…

When he got to the moving staircases, the Doctor again had to pause. They might call this enchantment, but he knew better- it was a simple clockwork mechanism that turned the staircases every few minutes. Even regular humans could make them at this point, if they wanted to.

"Hello there!" called a cheery voice to his left. Whipping around, the Doctor stared as the portrait of a young woman holding a baby _waved_ at him.

"Are you…talking to me?" he said warily. The 'ghosts' were one thing…but how on _earth_ had they transferred a temporal echo into a painting?

"Well of course I am! Where have you been the past twenty two centuries?"

The Doctor eyed the painting suspiciously. "Are you a temporal echo too?"

"A what?" the portrait lady looked confused. "No, I'm a painting of Lady Marabella and her daughter, Clarisse."

"So you _aren't_ actually Lady Marabella?"

"Well, not exactly, but I have all of her memories and characteristics. And I look like her as well." Lady Marabella's attitude turned from cheerful and bubbly to suspicious. "Shouldn't you know that by now?"

"Oh, well, this makes a lot more sense!" the Doctor said, relieved. "This would be an animation sequence, then. With artificial intelligence and memory strands integrated through the…paint." Much less confused now, the Doctor began up the stairs again.

"Good day to you, Lady Marabella!" he called over his shoulder.

"And…you as well…" Lady Marabella shook her head and tried to make sense of the strange man's words.

…

Finally, the Doctor arrived at the Astronomy tower. He pulled the note out of his pocket. Second door to the left of the tower…he turned around, looked to his left, counted down two doors, and pushed it open.

The room was plain and dark, with the only light coming from a tiny slit of a window on the far wall. The bed was small, but looked fairly comfortable. There was a desk in one corner. A sheet of paper lay on it, next to a bottle of ink, a brown quill, and a candle holder.

The Doctor frowned. These 'wizards' were obviously very advanced in technology, or magic. It didn't matter- did they _really _not have pencils or pens to write with? Or something a little more advanced than candlesticks for light?

The Doctor glanced down at the paper, reading the tiny words covering it in an instant. Lesson requirements for the fifth, sixth, and seventh years. Well, he was sure to cover it all…and maybe a bit more.

Also…according to this, dinner was supposed to start at 7:00 P.M. Even though the TARDIS was gone, his time sense was still intact, though much less sensitive than before. It was 6:52. He had better get going, since he was apparently supposed to sit at the 'head table' for dinner.

Pressing his lips together, the Doctor put down the paper. He would have a chance to explore the castle and his new classroom later. Right now, he had better leave.

Turning, the Doctor made his way to the Great Hall for his first evening as a teacher at Hogwarts School of Witchcraft and Wizardry.

**A/N Bit short this time, but hopefully still good ;). Review! Thanks to everybody who did!**


	6. Chapter 6

**A/N GAAAHHHHH I've been SO bad at updating! Shame on me. :( Our school musical just started AND I finally took my last midterm. Plus stuff before I start ninth grade. Blek. So, anyway, here's the chapter :)**

**Dark Dark Angel- If you like Eccleston, you're gonna LOVE Tennant and Smith. Ooooh yes. XD**

**Ilnae Dwin'itryn and Lydia-Hood- I'm sorry you didn't like the Snape part. :P It wasn't my favorite either, but I had to get him to trust the Doctor. Hopefully this chapter makes up for it. Also, Ilnae, thanks for the spelling ;) and Lydia- who said Voldemort was the one who pulled the Doctor into the new universe? ;) **

**STOP BLABBING CLAIRE AND GET ON TO THE STORY! ;) Okay, here it is.**

CHAPTER SIX

The Doctor sprinted through the unfamiliar hallways, thanking the universe that he had a photographic memory; otherwise he would _never_ be able to find his way back to the Great Hall. Even so, he was on the seventh floor of the castle and had to employ quite a lot of his naturally enhanced speed to reach the ground level in time.

Out of breath, the Doctor picked his way to the door that lead to the Head Table where he was supposed to sit. After climbing yet another flight of small stairs (honestly, who was the architect who designed this place?) he pushed open the heavy wooden door and entered the Great Hall.

Fortunately, there were very few students already seated, though what he assumed was the entire staff had already taken their places at the long Head Table. The situation was a little awkward, as he couldn't see any chairs left empty.

The humongous man he had met earlier (Hagrid, he remembered) was making beckoning motions under the table. The Doctor instantly realized that the man's huge girth was blocking his sight of the empty chair beside him. Gratefully walking over, the Doctor took his place between Hagrid and another woman with her grey hair done up in a severely tight bun.

More students had steadily been filing in, and now the room was nearly full. The Doctor sensed that it was approximately 7:01. Time for dinner.

Glancing to his side, the Doctor noticed the woman with the bun continually shifting her glace towards him every few seconds or so.

Smiling to himself, he finally spoke up. "You know, you could just _ask_ who I am."

The woman started, not realizing that he had seen her. She composed herself almost instantly. "Oh- I didn't mean to be rude. My name is Professor McGonagall, and you?" Her voice was almost as strict as her bun.

"Nice to meet you, I'm the Doctor," he said cheerfully. "No need to apologize- I've been rude before as well."

McGonagall nodded tersely. "I see. And…forgive me for putting this bluntly, but…who exactly _are_ you?"

"I'm the new Astronomy teacher. Dumbledore just…hired me today."

"Oh, so _you're_ the Astronomy teacher." McGonagall glanced at him sharply. "Dumbledore did mention there was someone new…"

"Yep, that would be me."

"I see," McGonagall said again. "Have you had much experience teaching?" she asked after a moment's hesitation.

The Doctor started laughing internally. _She thinks I'm too young to be a teacher. Well, how about I shock her a little more…_

"Experience? Me? Nah," he said. "I'm not even a wizard; I'm a muggle! With absolutely no magical ability whatsoever!"

McGonagall's eyes widened to the size of dinner plates. She sat completely still, in absolute silence. The Doctor felt a strange sense of accomplishment.

"A-and Professor Dumbledore…he still hired you? How…how did you even get here?" she stuttered.

"Well, I stepped into an enchanted police box, apparently, and wound up here," the Doctor said, casually throwing in his cover-up story.

"And you are to be the Astronomy teacher? You have…sufficient knowledge?" McGonagall said, trying to regain her dignified composure.

"Oh yes, probably more than you magic lot," the Doctor said. McGonagall nodded slowly.

"I…well, if Dumbledore thinks you are capable…then I suppose…"

Dumbledore stood up all of a sudden, cutting McGonagall short. "Welcome, Hogwarts students!" he said. His voice was magnified by the huge curved walls of the Great Hall. "Now before we become too occupied with our dinners, I have one short announcement. As you are all aware, Professor Aurora has…taken an extended leave of absence. You have, most unfortunately, found yourself without an Astronomy teacher. I am happy to announce that as of this afternoon, my friend the Doctor will be taking over her post."

McGonagall touched the Doctor's arm lightly, and motioned ever so slightly for him to stand up. Rising from his seat, the Doctor waved good-naturedly at the hesitantly applauding students. He could hear the slight murmur of confusion over his name and his sudden appointment, and he smiled happily before sitting down again.

"I'd also like to make you all aware that there has been a slight breach in security here," Dumbledore continued. The students all looked shocked, like they'd never heard of such a thing.

_So I'm the first to accomplish the impossible,_ the Doctor thought. _I always liked impossible._

"Under no circumstances should students approach the blue police box now located near the Whomping Willow, as the teachers and I believe it may be cursed, and if any of you found your lives in danger because your friend dared you to touch the box, I doubt your parents would be very pleased," Dumbledore finished. This drew out a slightly forced laugh from the students.

"Was that you?" McGonagall whispered under her breath to the Doctor. He nodded slightly. She pressed her lips into a very thin line.

"And now, I've held you from your supper for far too long." Dumbledore clapped his hands together twice, and mountains of food suddenly appeared on all the tables. "Dig in!" he concluded and sat down. The students eagerly began eating.

The Doctor stared at the food that had- supposedly- appeared from thin air.

_Don't scan it don't scan it don't scan it don't scan it don't scan it._

The Doctor slipped his sonic screwdriver out of his pocket and scanned the food. Yep, just as he had suspected- a clever teleporting system had brought it from a kitchen somewhere.

"What on Earth is that?" McGonagall said, blinking rapidly as she gazed at the screwdriver.

"It's a screwdriver," the Doctor said, holding it up for her to see. She raised one angular eyebrow. "It's sonic, it's a sonic screwdriver," he explained.

The eyebrow did not come down. The Doctor lowered the sonic screwdriver. "It's like…well, it's a screwdriver that I modified to stimulate the molecular activity in…" He could tell that his explanation was not going to help in the slightest. "Just call it my wand," he finally said.

"Mm-hmm." McGonagall lowered her eyes and stared at her plate, seemingly trying her hardest not to make eye contact with him, or even look at the Doctor in general.

Looking away awkwardly, the Doctor picked up his fork and prodded the mashed potatoes sitting on his plate. Well, they seemed real enough, and also seemed to biologically really be potatoes. There really was only one way to know for sure, though. The Doctor tested a bite of them. To his surprise, they had to be the best potatoes he'd ever eaten. They were even better than the potatoes he had eaten on Taylin, which was a planet devoted completely to the religion of worshiping roots and other 'gifts of the ground'.

Because Hagrid and McGonagall both seemed to be trying to ignore him, the Doctor leaned forward on his elbows, getting a feel for who his new colleagues were. There was a heavy man sitting on the other side of Dumbledore with a huge bushy mustache. He was talking animatedly with an exceedingly short man wearing a pointed purple hat. Next to them was a woman with huge round glasses and frizzy hair circling her whole head. She was wearing a dress covered in mirrors and bright flashing jewelry. Sitting beside her was another plump woman with rosy cheeks and a gardening trowel tucked into her robes, and then…

The Doctor instinctively frowned at the greasy, sallow face of Severus Snape, who was glowering down on the students. He could still remember Snape pulling apart his mind. The Doctor had dangerously underestimated the mental powers of these psychically enhanced humans, and had paid the price for it. He wouldn't make the same mistake again.

The Doctor suddenly stiffened as Snape's jet black eyes bored into his own. Neither of them blinked. Then there was a change- the Doctor could feel it. Out of the tiniest corner of his peripheral vision, the Doctor saw Snape slide his 'wand' out of his sleeve.

_Snape was trying to get back into his head._

_Not again, _the Doctor snarled mentally. _Not this time, slime-boy._

Snape was still pressing him. He didn't seem to be picking up on the Doctor's 'subtle hints' that he wasn't wanted. The Doctor firmly locked his mental shields into place. He could feel Snape's consciousness wavering just outside them, looking for a chink in his armour.

_If he thinks he can fight a full-grown Time Lord consciousness and win, he's got another thing coming,_ the Doctor thought bitterly. Snape still was circling his mind, searching for the non-existent entrances to the Doctor's thoughts.

The Doctor finally sent a thought to Snape. _Get out, _he thought firmly. _You're never going to break in._

Snape was still projecting a feeling of resilience.

_Never in a million years are you getting in, so you might as well save yourself the time and energy._

Snape still showed no signs of retreating.

_This is your last chance, Snape, _the Doctor growled.

No movement.

_Fine, _the Doctor thought. _Let's see how well __**you'd**__ take a mental attack._

The Doctor really didn't want to do this. But Snape was leaving him no choice. So without giving Snape another word of warning, he burst out from behind his barriers and attacked Snape's own head.

The Doctor almost smiled at Snape's surprise and alarm. He could sense the mental shields trying to be established, but in their early stages, he swept them aside easily. Now Snape was the one panicking to regain his mind. More powerful barriers were produced, but they were still not enough to prevent the Doctor invading Snape's mind.

As the last barriers fell, the Doctor felt a sense of triumph as he took complete control over Snape's mind.

Then a quiet voice in his own head whispered something that made him literally jump in shock. An echo of Rose's soft voice floated into his head-

_This isn't like you, Doctor. What are you doing to him?_

Blinking rapidly, the Doctor registered what Snape's physical face actually looked like in that exact moment. Snape looked completely terrified. His black eyes were wide and frightened. Searching Snape's mind, the Doctor realized that Snape's consciousness was, for lack of better words, huddled in a corner, trying to escape from the Doctor's overpowering presence.

He was absolutely terrified that the Doctor was going to kill him, then and there, simply drain and destroy his mind.

The Doctor released his iron-tight grip on Snape's mind, shocked at what he had done. _I'm sorry, _he thought weakly. _I'm so sorry…I didn't mean to…I'm so, so sorry…_He backed out of Snape's mind as Snape frantically regained control.

As he severed the last connection between his mind and Snape's, the Doctor felt light-headed and dizzy as his mind firmly clicked back into its place.

_What have I done? _

The Doctor didn't even want to look at Snape's face now, instead staring down at his hands lying in his lap. He was disgusted with himself. Just a few months ago, he never, ever would have done something like that. He felt like a monster. What was he turning into?

The Doctor pressed his lips together, ashamed. With the slightest glance to his left, he saw Snape stand up and walk out of the hall, obviously restraining himself from literally running from the room.

_You did that to him._

The Doctor felt a huge urge to escape from his own head. He was going to drive himself mad if he kept this up.

Rising from his seat, the Doctor turned to Professor McGonagall. "It was nice to have met you," he said in a clipped tone. She looked confused, but he turned away quickly, not wanting to explain himself.

What he really needed…he needed someone to talk to. Someone who would understand. Someone who he could pour out his soul to. Someone who would take the burden of his cares without complaint. Someone…like the TARDIS. But she, of course, was gone. Completely gone, forever.

The Doctor walked out of the Great Hall, making a beeline for his own room. Usually he didn't need rest, but right now…he had to escape from his own mind, and sleep seemed like the safest way. Maybe he would feel better in the morning.

For some reason, he highly doubted it.

**A/N So I don't update for a week and a half, and then I stick you all with a tiny little chapter again. :P MEH. Next chapter will cover the Doctor's first class, though, so it will hopefully be...entertaining. XD**

**REVIEW! YA KNOW I LOVE IT!**


	7. Chapter 7

**A/N This is really inexcusable, even by my standards. I AM SO SORRY THIS IS SO LATE! :( I've just been busy, I guess. I haven't even had time to read the comment thingies, so I'll reply to 'em in the next chapter because I really want to get this one up RIGHT NOW!**

CHAPTER SEVEN

Harry was sitting at the Gryffindor table between Ron and Hermione. While Ron and Hermione had no trouble at all eating the dinner, Harry was much too occupied watching the teachers up at the Head Table.

The evening had started off normal enough. He had come down to the Great Hall with Ron and Hermione, laughing and trying his best to forget the Doctor. Everything had gone downhill from there.

When Dumbledore introduced the Doctor as the new Astronomy teacher, there had been a lot of surprise and confusion. Nobody, except for Harry, Ron, and Hermione, had seen him before. He had just…appeared out of thin air.

Harry had been pestered with questions about the Doctor. What was he like, where did he come from, and why on earth was he called "The Doctor"? Harry really didn't know the answer to any of them.

However, it was after Dumbledore's speech that things got really weird.

Harry was absentmindedly picking at the usual delicious food, when he noticed something strange out of the corner of his eye. Glancing up at the Head Table, Harry was surprised by what he saw. Snape was _glaring _at the Doctor fiercely. The Doctor's expression was closed and guarded.

Slowly, however, Snape's face was changing. The malice was turning into…frustration? The Doctor had closed his eyes. Then, suddenly, they flew open, and once again, Harry swore he saw glints of golden light flashing from them.

Completely perplexed, Harry was startled to see what Snape's expression was now. It wasn't hate, it wasn't confusion, it was pure terror. What on _earth_ was going on? Looking back at the Doctor, he seemed…triumphant. Then the Doctor blinked a few times, and seemed shocked. Not at Snape, but with himself.

Snape stood up from the table. He was biting his lip hard. He walked out of the room without his usual sneer, instead trying to disguise the terror Harry had just seen him display moments ago.

A minute later, the Doctor left, looking disgusted with himself.

Harry looked around the Gryffindor table. No one else seemed to have noticed what he had.

"Harry? Are you all right?"

Harry looked to his left. Ron and Hermione were looking at him with curious expressions.

"I…yeah, I'm all right." He stood up from the table. "Come on, back to the Common Room, there's something I have to tell you about."

"But we just got started- oh brother," Ron said, getting up from his seat and running after Harry and Hermione.

…

"So let me get this straight," Ron said. They were gathered in the chairs surrounding the Common Room fireplace. There were a few other people in the room, so they were all whispering. "Snape was glaring at the Doctor."

"Yes," Harry said.

"The Doctor was glaring at Snape."

"Yes."

"Snape suddenly gets scared out of his mind."

"Yes."

"The Doctor looks triumphant, and then shocked."

"Yes."

"Snape leaves still terrified, the Doctor leaves still disgusted."

"Yes."

Ron nodded. "Okay. Weirdest story ever, but okay."

"Not okay," Hermione said. "We don't know what actually happened."

Ron looked at her funny. "Yes we do. I mean, me and Harry both told the story, _twice_, just now."

"I mean, _yes_, we know what happened, but we don't know what _happened._"

"Come again?"

"What she _means_ is," Harry interjected, "is that we don't know what went on between the Doctor and Snape."

"Oh."

"Maybe it was Legilimency," Hermione said. "Did Snape have his wand out?"

"I dunno…maybe he had it out under the table," Harry said. "Either way, didn't he already use Legilimency on the Doctor?"

"You told us earlier that Snape looked scared after he read the Doctor's mind the first time," Hermione said. "Didn't Dumbledore talk to you about the Doctor? Did he tell you anything about what Snape learned?"

"Er…well, actually…"Harry stammered. He sighed. "Dumbledore didn't actually…tell me anything about the Doctor. He…couldn't."

"What do you mean?" Ron asked.

"Dumbledore told me…" Harry hesitated a moment, looking around to make sure no one was listening. "Dumbledore told me that Snape refuses to tell him anything about the Doctor," he finally said in a low voice.

"_What?_" Ron shouted. Hermione shushed him.

"Snape just…said we could trust the Doctor. And that…"

"Yes?" Hermione prompted.

"He said that we didn't want the Doctor as our enemy."

Hermione looked shocked, and Ron looked confused.

"Well…that's ominous," Ron finally said.

"Yep."

"And Dumbledore still hired him, even though he was a muggle, and he didn't know anything about him?" Hermione asked.

"Yeah."

There was a moment of silence.

"Well…maybe we can ask the Doctor about it in class tomorrow," Ron said.

"Even if he doesn't tell us anything, I'm sure it'll be an interesting class," Hermione said.

"Yeah," Harry said, staring into the fire. "Interesting."

…

The next morning passed, for the most part, uneventfully. The only item of interest was between Charms class and Transfiguration. Harry and Ron were walking the halls together, killing time before they went to McGonagall's class, when they passed two Ravenclaw fifth year girls whispering together.

"He must be a muggle genius; I didn't know _anyone_ knew so much about Astronomy…"

"He's a good teacher. I've never learned so much in a class before."

"Not to mention he's so _handsome_…"

The two girls suddenly noticed Harry and Ron listening to their conversation. They both blushed scarlet.

"Are you talking about the Doctor, by any chance?" Harry asked.

"Oh, yes! Have you had him yet?" one girl asked eagerly.

"Um, no," Ron said. "We have him after lunch."

"Oooohh…" the other girl said. The two looked at each other and giggled.

"What? What's so funny?" Ron asked.

"Nothing," the girls said at the same time, and laughed again. "You're just going to have an…interesting class, that's all." The two ran off, still giggling together.

Harry stared after them and Ron raised his eyebrow in confusion. "Well, doesn't that make you excited?" he said sarcastically.

Harry didn't answer, still staring at the girls running away.

Ron sucked in a deep breath. "Well…better get to McGonagall's, then…"

Transfiguration passed quickly, as did lunch, where they met up with Hermione. Before Harry knew it, they were climbing the seven flights of stairs leading to the Astronomy tower.

Harry, Ron, and Hermione hesitated outside the door for a moment.

"Well…" Harry said. "Here goes nothing, I guess." He pushed open the heavy wooden door.

Most of the class was already seated. The Gryffindor sixth years and the Slytherin sixth years were sharing the period. Harry was a little disgruntled to see Malfoy sitting in the back of the room with a haughty expression. Harry, Ron, and Hermione sat together at a table near the front of the room. A little anxiously, they pulled out their textbooks and quills.

Harry took a look around. The classroom seemed mostly the same. There were star charts, rotating glass models of the universe on the tables, and a few telescopes pointing out the windows. However, he could see a few places where the Doctor appeared to have…modified. There were strange attachments affixed to the telescopes, and the glass models seemed larger, as though more galaxies had been added to them.

There was no sign of the Doctor.

"So…where is he?" Ron asked. Some of the people in the class had started to whisper together, wondering where the teacher was.

Suddenly, there was a loud bang from the closet. All the heads turned in confusion as light spilled out from under the crack in the door and there was another crashing sound.

The door flew open and the Doctor stumbled out, instantly turning around and slamming the door shut behind him.

"Good afternoon, class," he said cheerfully. Almost everyone had confused looks on their faces, except for Malfoy and some of the other Slytherins, who were sneering at the Doctor.

"Um, excuse me, sir, but…what were you doing in the closet?" Hermione said.

"Hmm? Oh, just getting things…ready," the Doctor said, turning to her.

Harry raised his eyebrows. Getting ready? For what?

"All right," the Doctor said, clapping his hands together. "Astronomy. Aaasssttrrrooonnoommmyyy. Astro nomy." He frowned. "'Physics' is more fun to say than 'astronomy'." He shrugged. "Anyway, on to the lesson. The first thing I should tell you- there's no such thing as magic."

There were several shocked exclamations from around the room, and some laughter.

"What are you _talking _about?" Malfoy scoffed from the back of the room. "This is a school of magic, _sir_."

"I'm well aware that's what you think, _mister _Malfoy," the Doctor said. "However, I'm afraid it's not true- magic is not real."

"Well then _what_ am I doing when I do this, sir?" Malfoy said. He waved his wand in the air, and his quill floated into the air.

"That is a complex series of electric currents that reverses the polarity of your quill and reduces the gravitational pull being applied to it," the Doctor said as he strode towards the back of the room. He plucked Malfoy's wand out of his hand.

"And this," he said, waving the wand in the air, "is not a wand. It's a telepathic molecular modifier. They are…well, were supposed to be extremely rare, up until a…few years ago when they were all…destroyed."

"Oh of course, sir," Malfoy said sarcastically. "It's a _'telepathic molecular modifier'._ How could I ever have been so stupid as to think it was a _wand_?"

"Well, maybe if you listened to what I was saying instead of scribbling notes to Miss Parkinson you would learn a thing or two," the Doctor said. "Maybe we could discuss this more in a detention after class? Would you like that?"

Malfoy's sneer disappeared. "No, sir," he mumbled.

Harry and Ron looked at each other, barely concealing their excitement at seeing the Doctor shoot down Malfoy.

"Anyway," the Doctor said, setting Malfoy's wand back down on his desk. "This year, you're going to learn a little more than just astronomy. I'm going to teach you about the whole universe, all the stars and planets that ever existed and will exist. Actually," he said, "I'm going to teach you about Time and relative dimensions in space." He smiled. "It's the TARDIS class."

Harry blinked, suddenly remembering the first thing the Doctor had said: _"Where's the TARDIS?" _Harry hadn't thought much of it at the time, thinking that he had probably misheard the Doctor, but now he wasn't so sure. Maybe the word 'TARDIS' had more significance than the Doctor was letting on.

Frowning ever so slightly, he turned his attention back to the Doctor, who was now drawing a one by four grid on the chalkboard.

"This is a punnett square. Does anyone know what that is?" he asked. Hermione's hand instantly shot into the air. "Yes, Hermione?"

"A punnett square is a grid used by biologists to predict the likelihood of certain genetic traits to be passed down through different generations," she recited.

"Very good, Hermione," the Doctor said. "You're absolutely correct. This certain punnett square is going to show how you all have your…'magic' abilities."

"A telepathic molecular modifier is tuned into your mind," the Doctor continued. "Only people with psychic abilities can connect with it. Your 'spells' help enforce the connection between your mind and the…'wand'. There are two basic things your mind has to have to integrate itself into the 'wand's' telepathic field: an advanced psychic ability, and an especially sensitive neurological system. Both of these are recessive genes."

The Doctor wrote two four letter sequences on the board: PpNn and ppnn.

"The 'P's stand for psychic ability and the 'N's are for neurological sensitivity," he explained. "The first person, say your father, has the PpNn code. He would not be a…wizard, I guess you would say because the dominant gene, the non-psychic ability and the less sensitive neurological system, is masking the recessive genes. However, the other person, your mother, has both recessive genes, and would therefore be a 'witch'."

He wrote a two-letter combination on top of the column and another four two-letter combinations alongside each row: pn on the top, and PN, Pn, pN, and pn on the side. He then filled in the column so he had four four-letter combos written: PpNn, Ppnn, ppNn, and ppnn.

"As you can see, if the only combination that allows you to be a 'wizard' is ppnn, then you really only have a one in four chance. That is, of course, assuming that both of your parents have a recessive gene somewhere and it gets passed along to you. This punnett square doesn't account for whether or not both your parents have 'magical' abilities, or if both of them do, or if one has both dominant genes. It also doesn't account to several other necessities that I'm not going to go into right now, or genetic mutations that may occur."

The Doctor put his chalk down. "Have I thoroughly confused you yet?" he asked.

Everyone's eyes were wide and confused. Only Hermione seemed to have the faintest idea about what he was talking about. There were several nods around the classroom.

"All right, then," the Doctor said. "I think that's enough genetics for today, then." He walked to the closet and grabbed the doorknob. "Are you all ready?" he asked.

No one seemed to know what to say. Ready for what?

"I'm going to take that as a yes," the Doctor said, and he pulled the door open.

Instantly the room was filled with…starlight. The walls, ceiling, and floor were covered with an incredible display of the universe. Swirling galaxies, shining clusters of stars, and the occasional comet were turning slightly around the entire classroom. It truly was breathtaking.

"But how did you…?" Hermione said in awe.

"I'm transmitting a map of the universe from a hologram projector in here," the Doctor said from within the closet. "It's a bit old, so the quality's not as good as some of the newer models, but it'll do for now."

The _quality wasn't good?_ What was he talking about? Harry felt as though he was literally floating in the middle of space, surrounded by stars.

"I thought this would make the classroom a little more interesting to learn in," the Doctor said, still beaming as he walked back to his desk. "The first thing we're going to learn about is the Andromeda Galaxy." He pulled out his funny metal screwdriver thing and buzzed at one of the galaxies. It zoomed up until the main focus of the projection circled around one of the stars.

"Now this star is called Omega 693," the Doctor said. "You might want to take some notes on this, it'll help with your homework. Omega 693 is more commonly referred to as Seculpa's Star…"

The next hour was the most enjoyable Astronomy class Harry had ever been in. The Doctor was so animated and fun to be around, and seemed to know the answer to every question a student might have. Harry felt completely comfortable with him, and the way he taught- actually _showing_ them stars and galaxies and nebulas- made Harry wish he never had to leave.

Inevitably, though, the class had to end. After showing them Omega 693's surrounding asteroid belt, the Doctor went back into the closet and switched off the projection, making Harry remember that he was still just in a classroom.

"All right class, that's all for today," the Doctor said. For the first time ever, Harry was disappointed to leave. "I want an astrology chart of Omega 693's galactic placement by Monday, and a punnett square with the genes PpNn for both parents filled in."

"Yes, Professor," Harry said. The Doctor blinked in surprise.

"Professor?" he said. "Oh, yes, right, I'm a professor now…" He smiled again. "Well, go on! Get to your next class!" he said to Harry and Ron.

"See you later, sir," Ron said as he pushed open the door.

"You as well, Mister Weasley," the Doctor said. "And you, Harry." Harry and Ron waved and let the door slam shut.

There was a moment of silence as they stood outside the door.

"Well," Ron said. "That was…"

"Interesting, yeah," Harry said.

"He's smart though, isn't he? For a muggle, I mean."

"Definitely, he's a genius."

There was another pause before Ron spoke up again.

"Reckon Hermione will fill in my punnett square for me?"

**A/N REVIEW! **


	8. Chapter 8

**A/N Thank you SO SO SO SO SO SO SO much for all your reviews! :D Enjoy the chapter!**

CHAPTER EIGHT

Harry threw his book bag full of textbooks down next to Ron and slid into a chair between him and Hermione. He was in the Defense Against the Dark Arts classroom, two classes after Astronomy. For some reason, Snape wasn't there yet, so he took advantage of his opportunity to talk to Ron and Hermione.

"So…Astronomy," he said in a low voice.

"Blimey…that was the best class I've ever had," Ron said.

"Definitely," Harry said. "First Astronomy class I've ever enjoyed."

"It was…informational, I'll give it that," Hermione said slowly.

"What? Don't tell me you didn't like it, Hermione!" Ron said, aghast.

"No, I liked it, but, well…" Hermione hesitated.

"But well what? Tell us, Hermione!" Harry said.

"Oh…it's nothing, it's just something I found out…"

"Hermione…"

"All right, Harry!" Hermione sighed. "It's just…well, the Doctor's a muggle, right?"

"Yes…?"

"And…and he's got muggle knowledge, right?"

"Where are you going with this, Hermione?" Ron asked.

"I'm getting there, Ron! So he's a muggle with an advanced knowledge of astronomy and technology."

"We have established that, yes," Ron said. Hermione shot him a withering glance.

"Well, last class, I talked to Professor Burbage, the Muggle Studies professor? I told her about the Doctor, and she told me…you know the things the Doctor was talking about? All those things about gravitational reversers, telepathic molecular modifiers, sonic screwdrivers, and whatnot? They don't exist!"

"What? Of course they do, the Doctor showed them to us!" Harry said incredulously.

"That's the thing – _muggles don't have that kind of technology. _And another thing – I have copies of some N.E.W.T. level textbooks, and there's _nothing_ in there about the galaxies and stars he was talking about."

"So what you're telling us," Harry said slowly, "is that either the Doctor is lying about being a muggle, or he _is_ a muggle with knowledge that's beyond muggles _and_ wizards?"

Hermione opened her mouth to respond when a sneering voice said, "If Mr. Potter is quite finished and ready to let me continue with my class?"

Harry, Ron, and Hermione looked up from their whispered conversation. Snape was glaring at them from the front of the room. Harry twitched his lip in slight annoyance at the snide look Snape always reserved for him.

"Sorry," Harry mumbled.

"Sorry, _Professor._"

"Sorry, Professor," Harry said through gritted teeth.

"Ten points from Gryffindor for talking during class."

Harry was about to protest at the unfairness of this, seeing how class had not even begun yet, but Hermione clamped a hand over his mouth.

"Not worth it, Harry," she whispered. Harry scowled and pushed her hand away.

"That's better," Snape said. "We will begin with nonverbal spells again, seeing as none of you seem to have grasped the very simple concept that all you have to do it _think _the spell in order to get it to work…"

The next hour was long and arduous, as each member of the class tried, and failed, to jinx their partner without saying a word. Only Hermione ever successfully blocked Lavender Brown's, albeit weak, hex nonverbally.

"Pity, pity…" Snape said as he passed Harry struggling to curse Ron, though the look on his face said otherwise. His lip was twisted upward in a scathing smile, and seemed highly amused by Harry's lack of success. "What's this, Harry? I thought you were supposed to be 'the Chosen One'. And you can't even manage to curse someone without screaming the spell!"

Harry tried to ignore him and focus wholly on jinxing Ron.

"Imagine how disappointed your parents would be…if they were still alive. I suppose you'll never know what a disappointment you are to them, will you, Harry?"

This last taunt sent Harry's patience over the brink. "At least I'm not scared of a muggle, _sir,_" he said coldly.

"I beg your pardon?" Snape said.

"Admit it, _sir_," Harry said, loading as much sarcasm as he could into the last word. "It's the Doctor. You're absolutely terrified of him."

"And what makes you think that?" Snape said. Harry looked at him – the sneer had slipped of his face momentarily, as soon as he had mentioned the Doctor's name.

"I saw you last night, at the Head Table, sir," he said. "I saw what happened between you and him."

"You might think you did, but you know nothing," Snape said.

"I saw enough." Harry paused, then continued. "Something about him makes your skin crawl. Just the _thought_ of him sends shivers down your spine."

"That's enough," Snape said sharply.

But Harry wasn't done yet. He'd been waiting to do this to Snape for a long time, and he wasn't going to stop now.

"You saw the inside of the Doctor's mind. What did you do, try and get back inside? Whatever the Doctor's done, it scares you to death. You can't stand the thought of him being in the castle. You're scared stiff of him."

"I said, _that's enough_," Snape hissed. "Detention, Potter. This Friday." Snape leaned in close to Harry, so that his hooked nose was just inches away from Harry's.

"You may think the Doctor is a fun teacher, and you may think he is your friend. You might even trust him. But you don't know anything about him, Harry. You don't know what he's done. You don't know anything," Snape said in a menacing growl.

Snape straightened up. The whole class was staring at him and Harry.

"Class dismissed," he muttered, striding into his office with his black cloak swishing behind him.

Harry packed his textbook and quill into his bag silently. Most of the class was still staring at him in fascination. Well, Harry had endured queer looks before. He threw his bag over his shoulder and walked out of the Defense Against the Dark Arts classroom with Ron and Hermione behind him.

As soon as they were out into the hall, Hermione finally spoke. "Oh Harry, why did you have to do that? How many detentions have you had with Snape already this year?"

"I don't know," Harry mumbled. "I just…he was making fun of my parents! He was _taunting _me about them!"

"Yes, I know, and it was completely unjustified," Hermione said. "But that doesn't give you the right to…to…"

"To what?" Harry said.

"Oh…I don't know, taunt him back?"

"It is a bit odd, though," Ron cut in. "I mean, everything Harry said was true – Snape _is _dead scared of the Doctor."

"Yeah," Harry said. "Don't you think that's a bit strange, Hermione?"

Hermione hesitated. "Oh, all right, it is a bit odd, but I'm sure there's a reason…"

"A reason Snape is so scared of a muggle?"

"Yes. And you know what else…everything you said to Snape was true, but everything _he _said was true as well. We _don't_ know anything about the Doctor. He could be anyone. He could have done _anything _in his life. Maybe something he's done is scaring Snape."

Harry pondered this for a moment. "Well…shouldn't we find out whatever we can about the Doctor then?"

"But…the Doctor's a muggle, there's not going to be anything about him, is there?" Ron asked. He looked at Harry and Hermione. "…Is there?" he said again, a bit more hesitantly.

"Well, if there _was_ any information on him, then it would be in…" Hermione started.

"The Library," Harry and Ron finished for her.

…

The Doctor reclined in his desk chair and stared at the ceiling, his hands clasped behind his head. His first week of teaching was over, and he believed that he had thoroughly confused pretty much every single student he had taught. They were all so ready to just accept that what they were doing was magic – they didn't have any other explanation, so he assumed 'magic' was a perfectly logical conclusion.

He knew better though. The kids weren't doing magic, they were using telepathic molecular modifiers. There were supposed to be only four that had ever existed, because they were incredibly powerful.

He, of course, had destroyed them all when he had ended the Time War.

The Doctor ran his hand through his hair, making it stick out all over his head. He had a _lot_ of questions, and no way to get answers. First of all, who was the being who had enough power to drag him out of his own universe and into this parallel one? Whatever it was, it had enough energy to break into his TARDIS and his own head, which really took _a lot_ of energy.

Second – where had these people gotten all these telepathic molecular modifiers? It wasn't as though they were a dime a dozen, though the way some of the kids used them, you would have thought you could find them in any little shop.

Third – how was he going to get out of this parallel universe with his TARDIS dead? And along with that, even if he somehow managed to escape back into his proper universe, what was he supposed to do without his time machine? He was a Time Lord stuck in one place and time forever, which really didn't suit him well.

The Doctor sighed and rubbed his temples. All the telepathic waves in the air were giving him a headache. Too bad he couldn't just take an aspirin…he would rather have a headache than be dead.

There was suddenly a knock on the door. The Doctor blinked in surprise, then stood up and opened the door. A blonde-haired girl with radish-shaped earrings stood there, staring at him with wide blue eyes.

"Uh…hello…?" he said, puzzled.

"Oh, hello, I'm Luna Lovegood," the girl said in an airy, unconcerned voice. She didn't elaborate; she just stood there with an amused expression.

The Doctor waited for a minute for her to speak. She didn't.

"Do you…um, is there a…reason you needed to see me?"

"What?" Luna blinked and shook her head slightly, as though waking up from a daydream. "Oh…yes, there is a reason."

She fell silent again.

"And…what would that reason be?" the Doctor said after another minute of silence on Luna's part.

"I'm supposed to give this to you," she said, holding up a small scroll of paper wrapped in a purple ribbon.

Again, there was _more_ awkward silence that Luna didn't seem to feel.

"Are you going to give it to me?" the Doctor said.

"Yes." Luna pressed the scroll into his hand, and then stood there like she was waiting for something.

"Okay…um…thank you?" the Doctor tried. She didn't move.

"Do you want me to read this now?" he asked.

"That would be nice, yes," she said.

"…All right…"

The Doctor unrolled the piece of paper and read it quickly.

_Dear Doctor,_

_I was wondering if you could stop by my office at 8:00 P.M. I am rather interested in how your classes are getting along, and would like to have a chat about them with you. _

_~Professor Albus Dumbledore_

_P.S. Sherbet Lemon is my favorite ice cream flavor._

The Doctor looked up from the paper. Luna was still standing there, but she had put on some strange looking sparkling glasses, with blue glass over one eye and purple over the other.

"Do you…um, still need something?" he asked uncertainly.

"Oh no, I was just looking at the Nargles in your room," she said.

"And…what exactly are Nargles?"

"They're invisible creatures that get in your head and make your brain go fuzzy. Your head is full of them."

"So…they're invisible, but you can see them?"

"Well of course I can, when I wear my Spectrespecs," Luna said as she gestured to her sparkling glasses.

"Ah. Of course," the Doctor said.

"I should be going now," Luna said. "It was nice meeting you, Doctor," she said as she turned and skipped away.

The Doctor had met a _lot_ of quirky people in his lifetime, but Luna definitely ranked among the top ten. He smiled slightly. He liked Luna. She seemed…interesting.

What time was it? It felt like it was about…7:37. He had twenty three minutes to get down to Dumbledore's office. He might as well start now – this castle had some of the strangest architecture he had ever seen, so who knew how long it would take him to find Dumbledore's office.

…

The Doctor found Dumbledore's office at 7:49.

The gargoyle swiveled its head stare at the Doctor with blank stone eyes. "Password?" it said in a deep male voice.

"Er…" The Doctor looked back down at the note. Surely Dumbledore wouldn't have sent for him without a password if he needed one to get into the office…

_P.S. Sherbet Lemon is my favorite ice cream flavor._

What? The Doctor read the postscript a few more times before realization dawned on him.

"Sherbet Lemon," he told the gargoyle confidently.

"Correct," it said, and moved aside so the Doctor could use the staircase behind it.

_Sherbet lemon, interesting password,_ the Doctor thought as he climbed the stairs and pushed open the door into Dumbledore's office.

It became apparent after just a moment that Dumbledore was not there. The Doctor took a good look around him. There were portraits covering nearly every inch of space. They seemed to be of different people who were all asleep. On closer inspection, the Doctor realized he could see them all breathing. Interesting. He wondered if they ever woke up.

There were bookcases lining most of the walls. Some of the titles were written in other languages. The Doctor put on his glasses and tried to read them. To his surprise, they quickly translated themselves into English. So…either the books had an automatic translating sequence, or maybe he had spent so much time in the TARDIS that he had absorbed enough background radiation to translate everything he saw.

The Doctor moved away from the bookcases and started examining the glass cabinets holding all kinds of devices he instantly recognized. Thermal radiation conductor… atom filter… interstellar plasmatic energy locator… temporal matter extrapolator… Dumbledore even had a vortex manipulator!

The Doctor continued down the line of devices, his amazement growing as he identified all the things Dumbledore really _shouldn't_ have, but did. He finally paused, though, when he saw a wide silver dish that seemed to be filled with water. Judging by the headache it was giving him, though, it really couldn't be that simple. He was just about to open the cabinet when he heard a sound that was…somehow…strangely familiar. It sounded like a chirp, but more…musical.

The Doctor turned around. Perched on a stand next to Dumbledore's desk was a large bird with beautiful scarlet and gold plumage. Its eyes, though…they were dark and ancient. The bird opened its beak again, and crooned softly.

The song was translated: _Doctor!_

The Doctor's breath hitched in his throat. He stumbled towards the bird, half afraid that if he got any closer, it would disappear. He had heard music like that before…he never thought he would hear it again…

The scarlet bird began to sing. _Don't you recognize me, Doctor?_

The Doctor's eyes were wide. It was too good to be true…no, it was impossible, there was no way it could really be…

_It's me, Doctor! _The bird sang.

"No…no, it can't be," the Doctor stuttered, absolutely shocked. "You're dead…I've seen you, you're gone…"

_Not dead, Doctor, never dead! _The bird sang. _Stolen. Not dead. Stolen. Hidden away… inside a body._

He couldn't believe it, he was making it up, it was all in his head…

The Doctor looked deeply into the bird's ancient eyes. It cocked its head to the side and stared back at him.

He wanted it to be true so badly…could it be real, could it be…

_Please, Doctor…it's me…_

"You're…you're the TARDIS. And you're…speaking to me," the Doctor said, his hands shaking, his eyes wide, waiting for the creature to deny it.

The bird didn't deny anything. It raised its magnificent wings in the air and began to sing, truly sing, right into the Doctor's mind and heart. It was the Gallifreyan love song he had been wishing for just days ago. The bird was singing the TARDIS's song, the sound he had always taken for granted, and now desperately needed.

The Doctor fell to his knees as the melody overwhelmed him. He hadn't realized exactly how much he had wanted to hear the TARDIS again.

"But…how…?" he croaked as the bird continued to sing.

_You were stolen from your universe. I was stolen from my home and hidden here._

"But that body…it won't last with you inside it…it's going to die…"

_Quite right, Doctor. I only have a few minutes left before it gives out._

The Doctor stared in horror at the bird that was his TARDIS. "You're going to die!"

_No…whoever imprisoned me has trapped the bird in a cycle of life and death. Watch!_

The Doctor watched. He saw the bird grow older and older. Then, suddenly, it began to shine with golden light, and burst into flames.

No, the Doctor thought. Not flames. Regeneration energy.

The bird crumbled into ashes. The Doctor ran over to the stand. The black ashes had fallen into a small dish beneath the stand. A small head peeped out, dusty and grey, but with shining intelligent eyes that were just as ancient as before.

"Are you alright?" the Doctor whispered.

_Always, Doctor._

The Doctor reached out to touch the baby bird's head, but it squawked in distress.

_No, DON'T!_

He hastily withdrew his finger. "Why? What's wrong?" he asked, worried.

_If you touch me, _he'll _know that you found me._

"What? Who's 'he'?" the Doctor asked. But at that moment, Dumbledore walked into the room.

"Ah, hello Doctor," he said. "I see you've met my phoenix, Fawkes."

"_Your _phoenix?" the Doctor said incredulously.

"Yes, _my _phoenix. I met him many years ago, and he took a liking to me. He has stayed with me ever since."

"Oh, the phoenix is a _he_?" the Doctor asked. He looked back at the bird, a half smile playing on his face.

_I didn't get to choose who I was trapped in, Doctor, _the TARDIS said. _It's not my fault the phoenix was male._

"Yes, Fawkes is a 'he'," Dumbledore said with an amused smile. "He has been my faithful companion for years."

"For _years?_" The Doctor frowned. _We only got here a week ago. _He looked at the bird. "Explain?" he murmured out of the corner of his mouth.

_When we were captured and brought here…_

But Dumbledore interrupted her. "Fawkes seems to have taken a liking to you, Doctor. He's very…talkative today."

"You'd be surprised at exactly how talkative 'he' is," the Doctor muttered.

"I beg your pardon?"

"Nothing," the Doctor said quickly.

Dumbledore smiled. "Very well, then. Let's get to business. How are you making out in Hogwarts?"

"But what about…" the Doctor glanced at the phoenix.

_Answer his questions, Doctor, don't act so suspicious._

The Doctor blinked and returned his focus to Dumbledore. "Right, yes…Hogwarts. It's going…fine, I suppose."

"Are you having any difficulty teaching your class?"

"None at all," the Doctor said with a smile. "It's kind of a natural thing, you might say."

"Good," Dumbledore said. "And now…I was wondering…if there is anything you wish to tell me." Dumbledore lowered his half-moon shaped glasses and stared at the Doctor with piercing blue eyes. The Doctor had the distinct feeling that he was being x-rayed. What if he told Dumbledore about being a Time Lord, about being stuck in a parallel universe, and about his TARDIS being trapped in the body of a bird?

"Nothing to report," he finally said. Dumbledore remained silent. The Doctor cleared his throat, a little uncomfortable.

"Actually, there is one thing," he said, just to break the silence. "I was looking at your…er…items, and I didn't know what this one was." He walked to the glass cabinet and pointed to the silver dish.

"Ah," Dumbledore said, walking over to the Doctor. "That is called a pensieve."

"A…pensieve?" the Doctor said. "Could you put that in more technical terms? I'm more likely to understand then."

Dumbledore smiled. "A pensieve is where I store my memories. I can…review them, you might say."

"What's wrong with using your head to store memories?" the Doctor asked.

"Do you ever feel like there is simply too much information crowded into your head?"

"All the time," the Doctor said.

"Well, a pensieve is where I store my memories when I run out of room in my head, you might say."

The Doctor raised his eyebrows. "So…it's a combination of neurological brainwaves and…storage space?"

"Something like that, yes."

"How do you use it?"

"Like this," Dumbledore said. He raised his wand to his temple and slowly pulled it away. A thin, silvery strand came away with it. Dumbledore tapped his wand on the edge of the pensieve, and the strand mixed in with the rest of the 'water'.

"I can now go back and review this memory if I want to."

The Doctor stared into the pensieve. He vaguely saw his own face in the liquid, and Snape's, outside Hagrid's hut.

"So…neurological brainwaves, replayed in a bowl. Interesting." The Doctor pulled out his sonic screwdriver. "I bet I have a setting for pulling memories out of my head." He twisted the end around a few times. "Would 53G work? Nah…maybe 691L. Or…aha! 91C! This one will probably work." He pressed the screwdriver against his head.

What memory should he pull out…oh, he had the perfect one…

The Doctor pressed the button, and the screwdriver began to buzz as it collected the memory. The Doctor pulled the screwdriver away from his head and let go of the button over the pensieve. A strand, not silver but gold, mixed with the rest of the memories.

_Don't get cocky, it's never good to meddle with your own memories_, he heard the TARDIS sing.

The Doctor smiled to himself. "Well, that was fun," he said. Dumbledore was giving his screwdriver a curious look. He slipped it into his coat pocket. "I think I'll be going now."

Dumbledore nodded. "Until next time, then, Doctor," he said.

The Doctor walked to the door, then turned around again. He locked eyes with the phoenix.

"Until next time," he repeated. Dumbledore nodded, but the Doctor was talking to the TARDIS.

_Doctor! When I was pulled out of my body, whoever brought us here had access to all of time and space for ten seconds, before he put me into the phoenix's body twelve years ago._

The Doctor blinked, trying very hard not to look very, very worried in front of Dumbledore. This was bad news. Very, very, very bad news. He took in a deep breath, then opened the door and walked out, his mind reeling.

**A/N OMDoctor, Fawkes is the TARDIS. XD There's something wrong with me, I swear…**

**REVIEW!**


	9. Chapter 9

**A/N PLEASE DON'T GIVE UP ON THIS FIC. Updates are going to be coming sooner, now that I don't have to practice 24/7 for this thing called String Fest and I actually have access to a computer. :/**

**Anyway, have a chapter. Yay. :)**

**(Oh, one more thing: I DON'T OWN DOCTOR WHO OR HARRY POTTER. Forgot that last time.)**

CHAPTER NINE

The Doctor practically sprinted down the stairs from Dumbledore's office, which was, by human standards, _really _fast. The moment he was off the staircase, he pressed himself against the hall's cold stone walls. His head felt like it was about to burst from everything he had learned and everything he _still _didn't know.

The TARDIS had been imprisoned inside the body of a phoenix for twelve years, even though the Doctor had only arrived in the universe a week ago.

Someone, somewhere, had enough power to pull a TARDIS straight through the Void into a parallel universe. Whoever had pulled him to this universe had had access to the whole of time and space at one point. This same 'someone' could also enter his mind, seemingly at will, and had erased part of his memory.

And he was _still _stuck here, even though the TARDIS wasn't quite as dead as he had thought before!

The Doctor groaned and slid down the wall, his hands covering his face. He had been in a lot of impossible situations before, but this might just top the list. He didn't even have a companion to help him this time; he was on his own. Alone.

He had to start finding answers to his questions. Dumbledore had basically trapped him inside the castle for who knows how long. If he wanted to learn anything, he was going to have to do it without Dumbledore finding out.

_What I really need is to be invisible, _the Doctor thought. _I don't need sleep at night. If I was invisible, I could find out anything when everyone else is asleep…_

How could he become invisible? The Doctor squeezed his eyes shut in concentration. There had to be a way. _Come on, Doctor, think! How are you going to become invisible?_

After a few minutes of intense thinking, the Doctor suddenly had a brilliant idea.

"A molecular scrambler!" he said rather loudly, jumping up off the floor in his excitement. He covered his mouth in surprise, afraid that someone might have heard him. A molecular scrambler would work, wouldn't it? If he could manage to get his molecules to all vibrate in sync at high speed, he could be vibrating too fast for human eyes to see him.

_It might not be enough, though, what with the increased telepathic fields._ The Doctor thought a little longer. _I should probably add in a perception filter, too. Just to be on the safe side._

Smiling secretly at his plan, the Doctor began to walk briskly back down the hall when another thought occurred to him.

_Can I even build a perception filter and a molecular scrambler without wires?_

The Doctor shrugged the thought away. There had to be wires _somewhere_ in the building. Building the molecular scrambler and the perception filter was going to be a piece of cake.

…

Harry slammed the heavy book shut, frustrated by how little information he had found. In another corner of the library, he heard Ron do the same.

Harry buried his head in his arms. There didn't seem to be _anything_ about the Doctor in the library. They had been looking for days, and none of them had found a single scrap of information about the Doctor.

A light tap on his shoulder made Harry poke his head out from his arms. Hermione was standing over him with a massive book cradled in her arms. Squinting at the cover, he could just make out the title: A Warlock's Guide to Dangerous Creatures.

"What's that?" Harry asked. He didn't see how a guide to dangerous creatures was going to help them in their hunt for information on the Doctor.

Hermione bit her lip, and then shoved the book into Harry's arms. The book was open to page 451. The page was mostly blank, except for a grainy photo of another book filled with spidery handwriting and a short paragraph beneath it.

Intrigued, Harry read the typed print under the photo.

_In 382 A.D., a man by the name of Carac Adeney wrote a most interesting entry in his diary. Recently discovered and translated, it provides an insight into what may be the most unknown and deadly creature of them all._

_Translated, this is what Carac Adeney's diary says about this elusive creature:_

"…_we came running back from the cave and through the village. The old man had told us of the fearsome monster, and we did not care if we were called town fools. The old man said that the monster was a trickster, drenched in the blood of thousands, nay, millions, or more. He would take our hearts and destroy our souls, and could not be killed by any of our means. He gave us wands to protect against this foul beast. But I cannot help but wonder if that will be enough to hide us from the Doctor."_

Harry blinked in surprise. The Doctor, a trickster drenched in the blood of millions? That was impossible. It was ridiculous!

But then again…something about him scared Snape…a lot.

Harry looked up at Hermione. She looked just as uncomfortable as he felt.

"So…you think it's true? That the Doctor was around in 382 A.D., and was a 'trickster drenched in the blood of millions'?" he asked her.

Hermione had a very strange expression on her face. "I…I don't know. I know it sounds impossible, but…I found something else. It's Carac Adeney's original diary."

She pulled a book out from behind her back and opened it a place somewhere in the middle. "This is the page they show in the book," she said. "It's the only mention of the Doctor's name in the entire diary, but I thought it was…interesting because on the back…" She turned the page over.

There was an illustration of a young man with glasses, spiky hair, and a metal cylinder that looked just like a sonic screwdriver. The caption read:

_The Doctor: The Most Deadly Creature_

…

The Doctor felt like throwing something at a wall. Making the perception filter and the molecular scrambler had been proving…more difficult than he had anticipated.

"Yeah, kind of hard to build a perception filter where there are _NO WIRES ANYWHERE IN THE BUILDING!_" the Doctor yelled at the ceiling. He had easily made the room soundproof with the sonic screwdriver (setting 34R) so he could be as loud as he wanted without attracting attention from anyone.

The Doctor collapsed in a chair in frustration. It was like someone had built the perfect prison for him: no electricity, no wires, basically no _anything_ that could be useful.

A sharp rapping on the door perked his attention. He got up from the chair and swung open the door. An owl was flying in circles around the classroom with a note clasped in its beak.

"Hey, come here," the Doctor said. "I think that's for me."

The owl landed on a chair and looked distrustfully at the Doctor.

"What is it with owls and hating me?" the Doctor mumbled. He held out a hand for the note. "Come on then, give it here."

The owl looked like it would rather do anything else, but it dropped the note into the Doctor's waiting hand.

"_Thank_ you," the Doctor said in a clipped voice. He unrolled the small paper.

_Staff meeting at 7:09 P.M. Teacher's room on the 7__th__ floor._

What time was it? 7:03. The Doctor had six minutes to find the teacher's room. He ran out the door, leaving the owl hooting indignantly behind him.

The Doctor just barely made it: at 7:08, he rushed into the room.

"Cutting it a little close, aren't we, Doctor?" Snape sneered from a seat in the corner.

"Yes, well, it's a little hard to find a single classroom in a seven story castle, isn't it?" the Doctor said cheerfully, taking a seat nest to a huge man with a walrus mustache.

The man sitting next to him turned and smiled. "Hello," he boomed. "I don't believe we've met! My name is Professor Slughorn, but please, call me Horace."

"Pleased to meet you, I'm the Doctor," the Doctor said, shaking the man's hand.

Dumbledore cleared his throat loudly. "If we are all here, I would like to begin." He paused a moment. "Now, as you may have guessed, we are gathered today to discuss the threat of Voldemort."

Everyone in the room seemed to shudder at the sound of the name, except for Dumbledore, Snape, and the Doctor.

"Oh, right, I remember him," the Doctor said. "He's the one you're all scared of, right?"

"You should be as well," Dumbledore said seriously. "He is a threat to wizards and muggles alike."

The rest of the teachers murmured in agreement. "Now, as you all know, Voldemort is once again approaching the height of his power…"

The Doctor raised his hand.

"Yes, Doctor?" Dumbledore said.

"Yes, sorry for interrupting, but you know, being the muggle that I am…what exactly does 'Voldemort' look like?"

"Well…he looks human, paler than usual, but with red eyes and slits for nostrils, much like a snake."

The Doctor thought about this. _Humanoid figure, pale to white coloring, with reptilian characteristics. _"This 'Voldemort' wouldn't happen to be a Vascalorian, would he?"

Dumbledore gave him a strange look. "A what?"

"Never mind."

Dumbledore seemed a little irked, but continued with his speech. "As I was saying, Voldemort is once again reaching the pinnacle of power he was at sixteen years ago. Hogwarts's defenses are formiddable, but as evidenced by the Doctor's arrival, Voldemort seems to have found a way to penetrate our protective spells, no matter how strong they appeared to be."

The Doctor looked a little uncomfortable at this. "Well, I don't know, maybe it wasn't _Voldemort_ specifically that...er...'enchanted' the police box. It could have been...someone else..."

"Like who, Doctor?" Snape sneered. "Do you know anyone else that could enchant a police box?"

The Doctor frowned at the smile twisting Snape's lip. "You'd be surprised," he said darkly. Snape's smile disappeared.

"As much as we would like to believe that it was _not _Voldemort trying to break into Hogwarts," Dumbledore said, "he has amassed so much power that there is no one else on this planet that could possibly have more skill and power than him."

_Not on this planet, maybe, _the Doctor thought. _But somewhere else? Most definitely. _

"Because of this, it is vital that we increase Hogwart's protection to maximum. Now, we need to lay out some plans for how we are to accomplish this..."

The Doctor raised his hand again.

"Yes, Doctor," Dumbledore said, his voice tinged with more than a little annoyance.

"Don't you think you're taking this a little too seriously?" the Doctor said quickly. "You don't know that it was Voldemort that brought the box here. It could easily be someone else. And anyway, 'Voldemort' can't really be that bad. I mean, he's not even trying to kill the _entire_ world, is he. It's just...erm...muggles. Which is a problem, but there's probably a very simple solution to all this..."

"I belive, Doctor," Dumbledore said, "that you are seriously misinformed if you think there is a simple solution to a villian trying to take over the world. It might help if you took things a _little _seriously."

"I do take things seriously! Just in a...light-hearted manner. When I have to take serious things _very _seriously, then someone is usually trying to enslave the galaxy, murder the human race, or destroy all of time, space, and reality."

Nobody responded to that. _Okay...maybe that was a bit much._

"Maybe I should just stop talking now," the Doctor said.

Dumbledore nodded tersely.

For the rest of the meeting, the Doctor did his best to remain silent, though he occasionaly started to explain the exact technological componets in the 'protective enchantments'. When Dumbledore announced that the staff meeting was over, he was the first one out the door.

Back in his room, the Doctor put his head in his hands, trying to sort through all the bits of information cluttering up his head. He exhaled sharply and stared at the ceiling. What he really needed were some _wires_. The moment he had electricity, he could build his molecular modifier and perception filter, and then he could get some _answers_. But where was he going to get those wires?

The Doctor closed his eyes in concentration. The last time he had had to improvise with human technology was...with Martha in New York, when he had built the DNA scanner. Where had he gotten wires then? He remembered: Solomon had given him a clock.

A clock!

The Doctor ran to the clock hanging on the wall of his room. Prying it off the wall, he opened the back and looked inside. Sure enough, there were a few wires hooked in, keeping the clock on schedule. The Doctor grinned as he carefully pulled them out; it wasn't as if he _needed_ a clock to know what time it was, and now he could get started building.

A few hours later, the Doctor completed the molecular modifier and perception filter, and was ready to start exploring the castle for _answers_.

**A/N YAY. :) I'm so sorry again for the REALLY late update! Review!**


	10. Chapter 10

**A/N Thanks for the reviews everybody!**

**Oh, and jaddedbfan: The love child of Moffat and Rowling? Dude, you _TOTALLY_ made my day! XD**

**Disclaimer: No Who. No Potter. Duh.**

CHAPTER TEN

The Doctor waited quietly in his room. He had blown out the light about 27 minutes ago to make it look like he had gone to bed and now he was just waiting for midnight so he could sneak out and start exploring the castle with his new molecular scrambler and perception filter.

11:16.

11:27.

11:43.

12:00!

The Doctor held up his sonic screwdriver to use as a light. Silently pulling the small devices out from underneath his bed, he flicked the power switches into the 'on' positions and latched them onto his pockets. There was a low humming sound as the machines engaged. The Doctor looked down, and was half surprised to find that he couldn't see himself. Good. That meant they were working.

The Doctor waited for the molecular scrambler and perception filter (the MS/PF for short) to quiet down. Then he carefully walked to the door. He almost tripped and fell over a few uneven boards a few times because he didn't know where his feet where. Eventually, he made it to the door, which creaked open at his touch.

The halls were almost pitch black. It was a good thing the Doctor had eyes like a cat; otherwise he never would have been able to find his way around.

The Doctor took a step forward.

_Wham!_

Stumbling back and cursing under his breath, the Doctor clutched his foot. He'd kicked the solid stone wall…_hard_. The noise carried easily down the hall. The Doctor immediately fell silent. He was going to have to be more careful.

After wandering up and down the hallway, plus accidentally kicking the wall a few more times, the Doctor got a feel for being invisible. If he went didn't sprint, he could get around pretty normally.

Now he was free to explore. The whole castle and the grounds were his. The only question was…where was he going to go?

The Doctor thought back to something he had told Rose ages ago, in Scotland. _Books are the best weapons._

He had passed by the library earlier that week. Yes, going to the library seemed like the best place to look for answers. Spinning on his heel (and almost falling over), the Doctor headed for the Hogwarts Library.

…

Holding the sonic screwdriver high over his head, the Doctor peered at the spines of the books. He didn't know exactly what he was looking for, which made looking…difficult. He frowned at the titles. _Prominent Brewers of the 16__th__ Century. Charm Help for the Magically Inept. A Warlock's Guide to Dangerous Creatures. Smiles and Spells: A Biography of Maverick Smith. How to Train your Dragon. _This was no help at all.

Running a hand through his already unruly hair, the Doctor groaned in frustration. He was getting nowhere. His light fell on the spine of another book. _Muggle Studies 101._

"Now why couldn't there just be a book called _How to Escape from a Parallel Universe After Being Possessed and Having your TARDIS Trapped Inside a Bird 101_?" the Doctor murmured, annoyed by his lack of success.

Sighing, he kept the light shinning across the books. _The Great Goblin Wars, Volume XVIII. My Life amongst the Werewolves. Hogwarts: A History…_

_Oooh, hold on a minute,_ the Doctor thought, going back to the "Hogwarts: A History" book. _Aha – history. History is good._

The Doctor pulled the book out from its place on the shelf. Judging by the thick layer of dust coating the cover, it was easy to assume that it wasn't the most popular book at Hogwarts.

Feeling a little excited, the Doctor pulled his glasses out of his pocket and set them on the bridge of his nose. Flipping the pages quickly, he speed-read the entire book in less than five seconds.

So…Hogwarts had been around for more than a century. That was a _lot___of little witches and wizards running around with telepathic molecular modifiers.

The Doctor frowned. Now, _there_ was something that really didn't make sense. Where were all these 'wands' _coming from_? They were supposed to be incredibly rare…well, nonexistent, since he'd destroyed the last four in all of time and space. And yet, there were thousands, maybe even millions, of "wizards" all over the world, all of them owning a telepathic molecular modifier.

Putting down the dusty history book, the Doctor began to scan the entire library for books on wands, particularly ones about wand history and origins. After walking up and down dozens of rows of shelves, the Doctor found himself outside a metal door locked shut. There was a placard welded to the front that read "RESTRICTED SECTION. NO STUDENTS ALLOWED WITHOUT A NOTE SIGNED BY A PROFESSOR."

Of course, this intrigued the Doctor quite a lot, so before he could think about it, he reset the sonic screwdriver and unlocked the door.

It was much darker in this room. There were no windows with moonlight streaming in. The books seemed older, and seemed to have an almost ominous feel to them. Undeterred, the Doctor began to comb over the shelves, once again using the screwdriver as a torch. A few times, he could have sworn he saw the books shift inside the shelves, and once or twice he was positive he heard footsteps behind him.

The books had more evil sounding names than the ones outside the restricted section. Running a finger over the spines, the Doctor grimaced at the titles. _Gruesome Hexes for Enemies. Blood and Entrails and their Uses. _Finally, his finger paused over one book.

_Wand Lore and its Origins._

Pulling the small volume off the shelf, the Doctor flipped it open. The pages crackled loudly as they were separated.

Readjusting his glasses, the Doctor squinted at a minute picture drawn on one of the pages. A group of people dressed in black were gathered around a shinning light. A twisted form was shown inside the light, holding a bundle of rods. Underneath the drawing was a caption.

"This is believed to be an illustration of wizards receiving the first wands from an unknown source. The original picture was dated in 382 B.C. The same year, the highly successful wand shop "Ollivanders" was opened for business."

Slamming the book shut, the Doctor was frustrated beyond belief. _"Receiving wands from an unknown source"?_ An unknown source! Why even include it in the book if you couldn't give any _useful _information!

The Doctor sighed. It was 4:37 in the morning. He really should get back to his room before anyone started waking up. He was invisible, true, but he could still walk into people.

Tucking the book under his arm, the Doctor left the library, disappointed for the moment.

…

_Dear Harry,_

_The time has come for our next lesson together. I have something quite important to show you. Please meet me in my office at 8:45 tonight. And don't forget – sugar quills are my favorite!_

_Dumbledore_

Harry slipped the scroll of paper back into his pocket. He'd been reading and rereading the note over and over again in front of the common room fire, trying to keep himself occupied before it was time to go to his lesson with Dumbledore.

"Hey Harry," Ron called from a table in the back corner of the room. "Do you have any idea what a 'snoozlegoot' is?"

"No," Harry said, getting up from his seat on the sofa.

"Neither do I," Ron said, shaking his quill. "This is supposed to be one of Fred and George's Spell-Check quills, but I think the charm is coming off. It keeps telling me that my maiden name is van Gough, and that by tapping three times on a lemur, it'll turn into a 'snoozlegoot'."

"What are you supposed to be writing?" Harry asked, pulling Ron's parchment over to his side of the table.

"Essay for McGonagall. Something about the changes a badger undergoes when it gets turned into a banana split bowl."

"Er…"

"That's what I said too," Ron said, sighing. "Have you got a quill I could borrow, Harry?"

"Er, yeah, just a second…" Harry reached down and pulled an older quill out of his bag. "Here you go."

"Thanks a million, Harry," Ron said, beginning to scribble down some notes on badgers and banana split bowls. After a few minutes of silence, Ron threw down Harry's quill.

"Ah, screw this. I'll ask Hermione if I can copy hers tomorrow," he said. He put his head down on the table. "Honestly, Harry, I really think the teachers are out to kill us."

"Have you done the Doctor's assignment yet?" Harry asked.

Ron's head shot up. "Blimey, I forgot all about that! Thanks for reminding me, Harry!" He pulled another piece of parchment out of his own bag. He stared at it for a while, his quill poised to start writing.

"Er, Harry…what was I supposed to write again?"

"You're supposed to do a punnet square for a PpNn mother and father."

"Oh, right." Ron started writing again. Harry watched him, more out of boredom than actual interest in what he was writing.

"Does this look right to you?" Ron said eventually, waving the paper under Harry's nose. Harry took it from him.

"Pretty much…no, wait, when you combine pN and PN, you get PpNN, not PPnN."

Ron scratched out the error and rewrote it. "All right, that's all I'm doing tonight. Snape's essay can wait for tomorrow." He packed the assignments away, and then looked up at Harry.

"Say, Harry, aren't you supposed to be at Dumbledore's right now?"

Harry whipped around and looked at the clock. 8:39!

"Yes I am!" he half shouted, jumping out of the chair and running for the door, accidentally smacking Seamus in the face in his hurry.

Fortunately, the hallways were pretty clear at that point, so he got to Dumbledore's office right on time.

"Good evening, Harry," Dumbledore said mildly from behind his desk.

"Good evening, Professor."

Dumbledore gestured at the vacant chair in from of him. "Please, take a seat, Harry."

Harry slid into the chair as Dumbledore stood up and went to his cabinet filled with memories. After searching for a minute or two, he plucked out a vial and returned to his desk. He put the vial into Harry's hand and settled back into his chair.

"Now, Harry. What can you tell me that is unusual about that memory?" 

Harry looked down at the strand inside the glass vial. "It's gold," he said, surprised. "I mean, the memory strand…thing, it's colored gold instead of silver." He looked up at Dumbledore. "Why isn't it silver?" he asked.

Dumbledore smiled. "I believe it is because that particular memory comes from none other than our friend the Doctor."

Harry blinked. "The Doctor? But…he's a muggle. He can't…you know…pull memories out of his head."

"Oh, I think you'll find that he can," Dumbledore said with a chuckle.

Harry still was not satisfied. "How did he get the memory out of his head? And when did you get it from him?"

"So many questions! To answer the first one, he used his…ah… 'screwdriver'. As to when I got it from him, I had the Doctor come here a few days ago, just to check in on him. He took an interest in my pensieve, rather like you, Harry. When I explained to him what it was, he pulled out his 'screwdriver' and pulled the memory right out of his head and into the pensieve."

"…Oh."

Dumbledore smiled kindly again. "I have visited this memory a few times already. I think it would be wise for you to see it as well." Dumbledore pushed the pensieve towards Harry. "After you, Harry."

Harry tipped the gold contents of the vial into the bowl and plunged his face into it.

He blinked, and found himself inside a forest. There was quite a lot of smoke everywhere, though Harry couldn't see any fire.

"_Come on Rose, it's coming!" _

"_I know, I know, I'm runnin' as fast as I can!"_

"_You ran right through its nest, it's not going to be happy with you!"_

"_Don' you think I know that, Doctor?"_

Two figures burst out from the trees, their outlines hazy from all the smoke. One was a man, tall with spiky brown hair. The other was a woman, blonde and shorter than the man. The Doctor and Rose, Harry assumed.

"_Quick, in there!" _said the Doctor.

A hand on Harry's elbow made him turn. Dumbledore was beside him, gesturing that Harry should follow the Doctor.

Harry went after the Doctor down a flight of metal stairs that he was sure hadn't been there before. At the bottom of the stairs, everything was still shrouded with smoke. The walls were made of shining metal, and monitors were beeping and flashing everywhere.

"_Rose, can you distract it for a minute while I get this all sorted out?"_

"_What, throw myself in front of it while you sonic everything?"_

"_Yup, that sounds about right."_

"_Hey, wait a minute, take this!"_

Harry saw Rose hand the Doctor a red bucket.

"_Oh, right." _The Doctor took the bucket.

All of a sudden there was a deafening roar, and Harry could feel the ground shake beneath his feet.

"_There it is!"_

"_Finish your sonic-in', Doctor!"_

The Doctor buzzed his screwdriver all over the screens. The flashing patterns changed forms.

"_Got it!"_

"_Doctor, it's comin' down the stairs!"_

"_Throw the bucket!"_

There was another roar, and suddenly Harry swore he saw a gigantic claw reach down the steps, thought he couldn't be sure with all the smoke. The blonde woman snatched the red bucket from the Doctor and threw it at the hazy shape. There was a screech, and the claw dissolved.

"_Nice throw, Rose Tyler!"_

"_Jus' finish your…sonic thing, Doctor, so we can get to the beach like we PLANNED."_

Harry felt Dumbledore tug on his elbow, and he was rushing up, until the scene dissolved and he was back in Dumbledore's office.

"What…what was _that?_" Harry spluttered, extremely confused by what he had seen.

"Oh, just a scene from the Doctor's memory. It was quite informative, I believe."

"Informative," Harry repeated incredulously.

"Yes, quite."

Harry shook his head. "Okay…well, that was interesting."

"It did provide a _very_ interesting insight into the Doctor's daily life."

"But sir…why am I seeing this? I mean…I thought I was supposed to be learning about _Voldemort's_ past so I can…you know…survive."

Dumbledore lowered his half-moon glasses and gave Harry a searching look. "If I show you something in one of my lessons, Harry, you have my word that it is most definitely vital for your survival, and of the utmost importance to us."

Harry looked at his trainers. "Sorry, professor. I just wanted to know…why I'm learning about Voldemort and the Doctor."

"The two are connected, Harry."

Harry frowned. "How can they be? I mean, the Doctor is a muggle."

"That may very well be, Harry, but I have a feeling…the Doctor has a part to play in our war, and it is just as wise to know your allies as your enemies…to decide who they really are."

**A/N Review everyone! :D More reviews = updates. It's a scientifically proven and Time Lord approved formula.**


	11. Chapter 11

**A/N Woo hoo, something is actually going to HAPPEN in this chapter! :D (AKA "this is not a boring filler chapter" XD) Soo…yeah. **

**Disclaimer: In case you were WONDERING, I don't own Who or Harry. I know, you all thought I did, but I don't. XD **

**On to the chapter!**

CHAPTER ELEVEN

Snow was falling fast and furious outside the Doctor's window, though the Time Lord didn't see it. He was too absorbed by the magical history book he was currently analyzing for the fifth time.

It didn't make sense. The "wizards" had _way _too much technology than they should. They had been using vortex manipulators ('time turners'), teleportation ('apparition'), and micro-gene chemical compound redistribution activators ('transfiguration spells') for _centuries_ at this point, even though the technology shouldn't have been available for another six thousand years!

The Doctor closed the book, slamming the cover a little harder than he had meant to. Rereading the history textbook hadn't revealed anything he had missed the first time around, and he was starting to get frustrated. He set the book down on a pile of notes he had been taking on every history book he could get his hands on. The notes were written in Old High Gallifreyan…he didn't know why he had chosen not to write them in English. Maybe he was just getting paranoid…but for some reason, he didn't want anyone to be reading them, even by chance.

With a resigned sigh, the Doctor scooped up his notes and settled back in his chair as he started to read them again.

"_Introduction of wands in 382 B.C. …received from an 'unknown source'…" _(There were some colorful swear words in Gallifreyan following that sentence.) _"Wands are made from almost virtually any kind of wood, though some are better than others, i.e. elder, holly, cherry, oak. …All wands contain either a) unicorn tail hair, b) dragon heartstring, c) phoenix feather, or d) Veela hair in some rare instances. …Dark figure arriving in light with first wands not necessarily from 382 B.C., could have traveled back in time with TARDIS's power. …Light source: light from interior of TARIDS? …Wizards have too much technology, centuries in advance, source most likely 'dark figure' in 382 B.C. …Dark figure may have access to my mind."_

The Doctor paused at the last sentence and pressed his lips together. He wasn't worried, why should he be worried that there was a strange creature with seemingly limitless power, possibly from a different universe, that could break into his mind at will?

Well…when he put it that way…maybe he did have cause to worry.

The Doctor shuddered ever so slightly and let the notes fall out of his hands and back onto the desk. He liked to think that he'd made progress in the past month, but really, all he'd found were interesting, slightly disturbing facts. He was nowhere closer to putting a face on the dark being than he'd been in November.

Suddenly deciding that if he waited in his room rereading his notes for a second longer he would go insane, the Doctor stood up, pushed the door open, and strode into the hallway, determined to do…something.

The snow outside the window caught his eye for the first time. Drifting over to the window, the Doctor cleared away the condensation and peeked outside. The snow was falling heavily, so that the entire countryside was blanketed in white. The lake was frozen over, and half obscured by the drifts of snow falling onto it. The whole place looked like a postcard. _Wishing You Were Here._

Movement in the corner of the Doctor's eye drew his gaze towards the entrance of the school. Squinting to try and make out the blurry black shapes, he eventually realized that they were the students in little groups walking down a path to who knows where.

The Doctor shrugged carelessly, and then turned away from the window and continued on his spontaneous walk down the hall, vaguely wondering where the students were going.

The Doctor eventually found himself at the main door of the castle. He hadn't been outside for quite a while. Apparently, Dumbledore's "request" that he remain on the school's premises did not include wandering around on the castle's grounds, supposedly because of the "Forbidden Forest" that the Doctor really was dying to go into.

The Doctor fingered the heavy metal doorknobs lightly. He had definitely been cooped up for too long…the snow and fresh air outside seemed far more compelling than it should.

A few straggling Hufflepuff third-years came tottering out of the Grand Hall, having just finished their breakfast.

"Excuse me, Professor," one of them said, reaching for the handle and pulling the door open. A gust of cold winter air rushed in, and the Doctor was surprised by how good it felt. The pair of Hufflepuffs walked outside, bundled up against the ice. One of them pulled the door shut, cutting off the wind blowing inside.

The Doctor frowned. He _really_ wanted to go outside. Everything about him was exasperated by his confinement within the castle.

The sound of footsteps clattering down the stairs turned his attention away from the closed doors. The Doctor was more than a little surprised to see Slughorn and McGonagall coming down the stairs, both of them wearing thick coats, scarves, and hats. Slughorn's scarf was extremely long, to wrap around his wide neck several times over, and the Doctor was suddenly reminded of his fourth regeneration's appreciation for long scarves.

"Er…are you…going somewhere?" the Doctor asked.

"Well, yes, we're on our way to Hogsmeade Village!" Slughorn boomed. "Last trip of the year, you know. All kinds of fun down in the village."

"And…Hogsmeade is…?" The Doctor's voice trailed off.

"Oh, you're a muggle, I simply keep forgetting that! Hogsmeade is an all-magical village just around the corner of the school grounds. The students and the teachers get a chance to visit every now and then. Minerva and I were just on our way for a quick trip. I would think you would like to come along as well, m'boy!"

"I'm not allowed. Dumbledore's asked me to stay inside the castle for… security reasons," the Doctor said.

"Poppycock! Even Dumbledore wouldn't object to a quick trip into town and back, I think. You can't stay inside forever; it's not good for a young man like yourself!"

"I think the Doctor raises a good point, Horace," McGonagall said a little stiffly. "Dumbledore _did_ say…"

Slughorn waved a hand in the air, as though he was dismissing her words. "Ah, don't worry about Dumbledore, I'll just pop into his office later to let him know. After all, it's nearly Christmas, surely he'll let the Doctor off this once." He clapped the Doctor on the back. "Come on then, there's a good man. Let us go before this blizzard gets any worse."

The Doctor pressed his lips together. On one hand, Dumbledore had told him to stay inside, and he didn't want to break his trust so soon. On the other, he really had been cooped up for quite a while, and it would be great to get outside again…

"What do you think, McGonagall? D'ya think Dumbledore will let me off for Christmas?"

McGonagall seemed just as uneasy as the Doctor, but she did look a little sorry for the Doctor. "Well…oh, perhaps you should. It is Christmas, after all."

The Doctor's grin was a mile wide. "Brilliant! Let's go!" He pulled open the front doors and a blast of cold air whirled inside.

"Hold on Doctor, don't you want to put on something a bit warmer than that?" McGonagall said.

The Doctor looked down. He was wearing his blue suit, red converse, and tan trench coat. The other teacher's didn't know that he could withstand much more extreme temperatures than them, and that the 'blizzard' outside was barely making him shiver.

"Nah, I'll be fine. No pain, no gain, right?" he said, practically running outside.

The snow was falling in thick, wet flakes that landed and stuck to the Doctor's hair and eyelashes. The air was cold and crisp like ice as he sucked in deep breaths of the wonderful, sharp fresh air. He felt more alive than he had for a month. He closed his eyes and smiled, relishing the feel of wind and snow blowing against him. Oh, he had missed this. How on earth had he survived for a month without going outside?

There was a chuckle from behind him. Turning around, the Doctor saw Slughorn laughing quietly behind his hand.

"What?" the Doctor said, grinning.

"You really are the outdoorsy type, aren't you?"

After thinking about this for a second, the Doctor responded with "I guess you could say that."

"It shows." Slughorn laughed again. "You took off like you were running from an alien invasion!"

"Er…yeah…heh," the Doctor laughed weakly. "Alien invasion. Funny."

Slughorn didn't seem to notice his lackluster response, however. He was reaching into his pocket and pulled out a piece of paper tied with a neat little lilac bow.

"I'm having a Christmas party next week," Slughorn said, handing the Doctor the invitation. "You seem like you would be _quite_ an entertaining guest."

"Er, yes, thank you," the Doctor said, stowing the invitation away inside his own extensive bigger-on-the-inside pockets.

The rest of the walk to Hogsmeade was rather uneventful. Slughorn chatted the entire way, going on and on about his past students, his connections in the political world, and what his opinions were on every issue that had arisen in the past fifty years. The Doctor wondered briefly if that was what he sounded like to his companions.

When they reached Hogsmeade, the three parted ways. McGonagall seemed quite anxious to get away from Slughorn, something the Doctor couldn't exactly blame her for. As Slughorn meandered into the sweetshop, the Doctor headed off for the center of town, peering in windows and exploring the "magical" village.

The town seemed busy enough, but with the cold weather, there was hardly anyone outside; they were all inside the shops, trying to stay warm. There also seemed to be quite a lot of boarded-up shops. The Doctor wondered how business could be bad with hundreds of magical students stopping by every few weeks.

A shout from behind him made the Doctor start violently. His hand automatically flew to his pocket and he pulled out his sonic screwdriver as he whirled around. To his surprise, he saw Harry Potter pinning a small, scruffy-looking man to the wall. There were several grubby-looking objects scattered on the ground around the man's feet. Harry had his wand pressed against the man's neck. _What?_

Determined to find out what was going on, the Doctor slipped into an alley just around the corner from where Harry was pinning the man to the wall. Trying to keep his breathing as silent as possible, the Doctor glanced around the corner, just barely making out what was going on.

"You took that from Sirius's house. That had the Black family crest on it."

"I – no – what – ?"

"What did you do, go back the night he died and strip the place?"

"I – no – "

"Give it to me!"

"Harry, you mustn't!"

There was a bang. The Doctor couldn't see exactly what had happened, but from the volume and ferocity of Harry's swearing, it couldn't have been good.

"COME BACK, YOU THIEVING – !"

A new voice appeared. "There's no point, Harry?"

Daring to look even further around the corner, the Doctor saw a thin woman with mousy brown hair and sad eyes talking to Harry.

"Mundugus will probably be in London by now. There's no point yelling."

"He's nicked Sirius's stuff! Nicked it!"

"Yes, but still, you should get out of the cold."

The Doctor made out the forms of Harry, Ron, and Hermione walking into a building and out of sight. The woman looked at the sky, her sad brown eyes filled with loneliness. She raised her own wand and disappeared again.

Feeling that it was safe to come out from his hiding spot, the Doctor glanced at the board proclaiming the title of the building Harry had gone into: The Three Broomsticks. Now very curious, the Doctor slipped into the pub behind them.

The inside of the building was warmly lit by candles and a roaring fire. There were people laughing and talking loudly over their drinks. Perfect – it would be easy to get lost in the crowd. He didn't want Harry, Ron, or Hermione to see him and think he was following them which, of course, he was.

Sliding into an available seat at a small table near the back of the pub, the Doctor scanned the crowd for the trio. He finally spotted them in a table next to the left wall. Hermione seemed to be attempting to calm Harry down. The Doctor watched them talk, unfortunately not able to hear anything they were saying. After a few minutes, they stood up. None of them looked very pleased, and seemed like they were ready to leave. Cautiously rising as well, the Doctor was about to make his way to the door when something rammed into him.

"Sorry, Professor," said a monotone voice. The Doctor was surprised to see Katie Bell standing next to him, holding a package in one hand.

"That's fine, Katie," the Doctor said. Katie was turning to leave when the Doctor reached out and grabbed her wrist.

"Hang on a minute, Katie," he said, squinting worriedly at her. Her pupils were dilated, and underneath his fingers he could feel her pulse thrumming at an abnormally fast speed.

"Katie, are you all right?" he asked. "You're really not looking yourself, you know…"

"Sorry Professor, I have to go now," Katie repeated, pulling her hand out of the Doctor's grip and weaving her way through the crowd, where she was joined by another student named Leanne.

_What?_

Something was very out of place. Waiting until Harry, Ron, and Hermione left the pub, the Doctor headed out with the ominous feeling that something very, very bad was about to occur.

…

Harry drew his cloak tightly about him as he, Ron, and Hermione started their walk home. The wind was howling around them, and he could barely see through the swirling white snow. His exposed face felt like it was being cut by tiny cold knives. Next to him, Hermione shivered violently and Ron sneezed.

After walking for a few minutes on the High Road back to the school, Harry realized that he could hear Katie her friend Leanne arguing loudly about something. Trudging through the snow, their voices became shriller and louder. The first words he could properly make out were from Katie.

"It's nothing to do with you, Leanne!"

Barely able to see through the sleet and ice coating his glasses, Harry saw Leanne try to tug something out of Katie's hands. The object fell into the snow, and at once, Katie flew up into the air.

Instantly Harry knew there was something wrong. Katie was completely still, six feet in the air, her arms outstretched like wings. It was eerily silent. Even the wind seemed soundless. Katie was completely expressionless. Watching in fascination and in horror from the ground, Harry jumped when Katie started to scream.

She was screaming as though she had been stabbed by a white-hot sword. It was a terrible sound, a sound of pure anguish and agony. She was writhing in midair, twisting and shrieking as she tried to escape the pain. Her eyes were rolling madly in her head as she convulsed. The wind began to scream again, whipping around Katie like a demon.

Leanne started to scream, and tried to tug Katie back to the ground. Harry, Hermione, and Ron were about to help her when there was a shout from behind them.

"_Get back!_"

A tan and blue object rushed past the group and knelt on the ground beneath Katie.

It was the Doctor.

"What – ?" Harry started to say, but the Doctor wasn't listening. He had pulled out his metal wand and was twisting the end around frantically, searching for something. He finally pointed the wand at the package beneath Katie and pressed down on the blue button. There was a whistling sound, and Katie fell to the ground, landing hard in the snow. She didn't appear to have noticed, however, and continued to shout and thrash.

"What are you doing?" Leanne sobbed as the Doctor knelt next to Katie and pressed his fingers against her temples. Katie squirmed beneath his hands as the Doctor closed his eyes in concentration. After a moment, a final shudder ran through her as her eyes closed and she stopped moving.

The Doctor opened his eyes and let his hands drop back to his sides. He exhaled sharply, as though he was trying to catch his breath.

"What happened?" he said, turning to Harry.

Still in shock, it took Harry a moment to answer. "Er…I don't know, Leanne was talking to her about that…that package thing, and then she just…she just rose up into the air and started screaming." Katie's screams were still ringing in his ears, bouncing around inside his head like an echo.

"Where's the package?"

Harry pointed to the brown speck in the snow a few feet away. Moving over to examine the package, the Doctor pulled out a pair of square glasses and put them on. Twisting the end of his metal wand one more time, he ripped open the package's paper, revealing a necklace inside. The Doctor pointed his wand at the necklace. After a few seconds he tore his glasses off again.

"Incredible," the Doctor said. "It's a necklace made of frozen Krillotain oil."

"Frozen _what_?" Ron said, confused. "Speak _English_, please."

"It's changed since I last saw it…last time the oil just burned someone like an acid…the Krillotains must have absorbed some sub-zero weather species to get their oil to modify like this…"

Ron reached forward to touch the necklace, but the Doctor grabbed his hand. "Better let me do this. You saw what happened to Katie…"

"What, and you can touch it?" Ron said sharply, though his voice cracked halfway through; he was obviously scared.

"I'm no lunch lady," the Doctor muttered. After looking at the necklace for another moment, he reached out and picked it up. After a minute there was a crackling sound, and the Doctor dropped the necklace back into the snow, biting his lip and looking at his palm. There was a red scorch mark running across his hand.

"It's gotten stronger, or maybe it has something to do with the freezing…"

The Doctor stood up and shrugged off his coat.

"What are you doing? You'll freeze!" Hermione said. The Doctor ignored her. He picked up the necklace and quickly stuffed it into one of the pockets. Then he walked over to where Katie was lying in the snow and wrapped it around her. He picked her up and started running back to the school.

…

When the Doctor burst through the front doors of the castle carrying Katie in his arms, he realized that he had no clue where the hospital wing was.

Harry, Ron, Hermione, and Leanne hurried in after him.

"Hospital wing?" the Doctor asked, looking for an answer from one of them.

"This way," Harry said, pointing to a staircase on the right.

"Right, Harry, I want you to show me where the hospital wing is, and I want Ron, Hermione, and Leanne to go get McGonagall and tell her to meet me up there. She should be back from Hogsmeade by now."

Ron and Hermione nodded and ran off in the opposite direction. Leanne stayed where she was.

"Please, Professor, can I come with you?" she sniffed. "I want to make sure that Katie…that she's going to be…"

"Yes, you can come, we just need to hurry," the Doctor said in a rushed voice. "We've got to get her up there right away."

Harry led the Doctor and Leanne up to the hospital wing on the sixth floor. Leanne pushed the doors open as the Doctor carried Katie inside and laid her down on a bed.

"Madame Pomfrey!" Harry shouted. "We need you!" 

Madame Pomfrey came bustling out of her office. Her hand flew to her mouth as she rushed to Katie's side. "What happened to her?" she asked. She didn't wait for an answer, however, as she ran to a medicine cabinet and began pulling out different bottles.

Soon afterwards, Professor McGonagall came rushing into the hospital wing, followed by Ron and Hermione. "Good gracious, what has _happened?_" she exclaimed.

Leanne started to tell the story in a halting voice as she tried to choke back her sobs. By the time she reached the part of the story where Katie had risen into the air, she was practically hysterical. Madame Pomfrey gave her a potion for shock and led her into a chair to sit down for a while.

McGonagall seemed quite shocked by Leanne's story, though she maintained her composure well. She looked down at Katie's prone form. "The poor girl, she must have been Imperiused by someone in the Three Broomsticks." She glanced up at the Doctor. "Where did you come in during all this?" she asked.

Harry took up the story from there. Afterwards, McGonagall had a strange expression on her face, but she didn't say anything much.

"Thank goodness Horace gave you the idea to go to Hogsmeade today," she said to the Doctor. "I shudder think what would have happened…well, I'd rather not think about that." She looked at Katie again. "Do you have the necklace that she touched?"

The Doctor blinked. "Oh…oh, yes! Right, um, here it is." He reached into his pocket and quickly pulled out the necklace.

"No, don't touch it!" McGonagall practically shouted.

"Sorry!" the Doctor said, dropping it.

McGonagall waved her wand and the necklace floated into the air. After looking carefully at it, her expression changed to one of utter disbelief.

"This…this necklace is cursed by incredibly powerful Dark Magic. Katie must have brushed against it with just a tiny hole in her glove…touching it directly would have killed her instantly." She stared at the Doctor, her eyes wide. "You should be _dead_, Doctor!"

"Oooohhh…" the Doctor said. "Um, right, well…lucky me, I guess?"

McGonagall couldn't seem to tear her eyes away from the Doctor. "But how…?"

The Doctor shrugged. McGonagall didn't seem quite satisfied by this, but she didn't press the matter further. She sank into a chair beside Katie's bed.

The Doctor was groaning inwardly. Now she was going to be _very_ suspicious of him…even more so than before.

He looked down at Katie's still form. She shouldn't have had to go through all that pain. If only he could have gotten there sooner…if only he had been a big quicker…

If only. The two words that summed him up entirely.

If only.

**A/N Go ahead and review :) I expect someone to be the 100th reviewer! :D**


	12. Chapter 12

**A/N Wow, thanks for all the reviews! :D Congrats to PhoenixRe for being the 100th reviewer! **

**Enjoy the chapter!**

CHAPTER TWELVE

Harry pushed the door of the Astronomy classroom. This was the last day of classes before school let out for the winter holidays. Astronomy was really the only class he had actually been enjoying recently. Every other class was loading him down with mountains of homework. Astronomy so far had been fairly easy going. Thank goodness for that – Harry didn't think he'd be able to handle another class as difficult as Transfiguration.

Harry, Hermione, and Ron were the first ones in the classroom. They had left lunch a little early; none of them had had much of an appetite after watching what had happened to Katie Bell a few days previously.

"Hello, Professor," Hermione said. The Doctor was standing on a tall ladder, fiddling with something along the high windowsills.

"Hmm?" the Doctor said, looking down. "Oh, hello kids. Is it time for class already?"

"Er, yes," Harry said. "Um…Professor, I have a question for you." Harry had had a question for the Doctor for quite a while now, ever since he had seen that memory in Dumbledore's pensieve, but hadn't found an appropriate time before now.

"Fire away, Harry," the Doctor said, still buzzing at the windows with his screwdriver.

"All right…um…who's Rose Tyler? And where is she if she's not with you?"

The Doctor started so violently that his foot slipped off the top rung of the ladder and he fell five meters before crashing to the ground.

"Professor!" Hermione half-screamed. She, Harry, and Ron ran over to where the Doctor had fallen, but he was already standing up and brushing off his shoulders.

"Where did you hear that name?" the Doctor said, staring deeply into Harry's eyes. He didn't seem to care that he had just fallen far enough to break his ankles.

"Sir, are you oka-" Harry started to speak, but the Doctor cut him off.

"Never mind that, Harry, _where did you hear about Rose Tyler?"_ The Doctor's voice was urgent, as though the matter was of the utmost importance to him. He put his hands on Harry's shoulders. "Where, Harry? Is she here?"

"I don't know if she's here, I just…um…heard someone talking about her and you, and I was just wondering where she was," Harry lied quickly. He didn't want the Doctor to know that he'd seen his memory.

The Doctor sighed. "You're lying, Harry," he said quietly. He let his hands drop off Harry's shoulders. "But you honestly haven't seen her here?" he asked expectantly.

Harry felt a little abashed that the Doctor had caught his lie. "No," he said, letting his gaze drop to the floor.

The Doctor bit his lip and turned away from Harry. More students were starting to filter into the classroom.

"Take a seat, you three," the Doctor said, disappointment heavy in his voice. Harry and Ron slid into seats in the back, while Hermione sat in the very front. She and Ron were not feeling particularly…amiable towards each other at the moment.

"Well, that was weird. Doesn't he realize he just fell off his ladder?" Ron whispered to Harry before the Doctor started the class.

"Well, it's the last day of class before the holidays," the Doctor said, a grin pasted onto his face again. Harry was surprised by how quickly his mood had changed from extreme disappointment to giddy excitement. It seemed that his quirky, happy appearance was a mask for a much darker personality.

"…and I'm sorry to disappoint you, but you have to take a mid-year test today," the Doctor said. There were several groans around the room, but the Doctor looked genuinely apologetic.

"I know, I know, it's a rotten piece of luck, but at least the day's almost over and you can all go home tomorrow, right?"

Well, Harry thought, that's true for everyone but him.

The Doctor started passing out rolls of parchment with the test printed on them. Harry sighed as he looked down the list of questions. They weren't terribly difficult, but they'd covered a lot of material during the year and he wasn't sure he'd be able to remember everything from September.

For the next forty-five minutes, the class was silent except for the scratching of quills on the paper. Everything passed by fairly uneventfully, until the last few minutes of class as Harry was approaching the last questions.

_Give the names of the three planets orbiting Babel Fis 42 and describe their physical characteristics._

Harry bit his lip in concentration and was about to start answering the question when he felt a cold tingling sensation on the back of his neck. It was as though a chilly breeze had just swept across him. Confused, Harry turned around in his seat and looked at the students behind him. It was just Lavender and Parvati. Parvati was completely absorbed by the questions on the test, and Lavender was making kissing sounds with her lips, focused solely on the back of Ron's head.

A little disgusted, Harry faced forward again, his face twisted in confusion. Had he just imagined the sensation?

Another frosty breath dispelled that theory. Harry sat up straight. No one else seemed to notice the cold wind that had crept into the classroom; they were too focused on finishing their tests.

Something strange was _definitely _going on as a third gust of the impossible wind sent shivers down Harry's spine. It felt…stronger. More powerful.

Harry was no stranger to evil. His whole family had been murdered when he was just one year old. The most powerful dark wizard in history had tried to kill him six times already, and he was just sixteen years old. He _knew_ when something was evil. He could _feel_ it.

The gusts of wind that blew around the room like ghosts that no one else could see were dark. Harry didn't know exactly what they were, but it was safe to assume that they were far from being good.

His first thought was that the dark winds were there for him. He'd been threatened pretty much his entire life. It made sense that Voldemort would have found a way to send his minions into the castle.

But the longer Harry thought about it, the less it felt like that was the right answer. The winds were brushing past him, hardly taking any interest in him. It sounded insane, even to him, that winds could have thoughts, but the winds were feeling less like ghosts and more like tangible creatures with every second that ticked by.

Harry could feel it; he was a random passerby who, just by chance, was watching something much more dramatic play out in the classroom. The winds were whistling past him, unintelligible whispers carried by the frosty gusts. They were gathering together, converging on one point in the front of the room.

Harry was vaguely aware that he was trembling as he scanned the front of the room from under his eyelashes. There was nothing up there, just the chalkboard, the star chart, and the old wooden desk where the Doctor was sitting, grading essays.

…The Doctor.

As soon as the Doctor's name popped into Harry's head, he was sure he had found his answer. The only thing the ghost winds could be closing in on was the Astronomy professor.

The phantom gusts were getting thicker and darker, and still no one could see them. They were clustering around the Doctor, beginning to whirl in a dark cloud around him. Harry saw the Doctor suddenly blink and look up, as though he had just sensed that there was something wrong.

Harry had to say something. He put his hand in the air. "Sir- " he started to say, when the dark winds all dove at the Doctor at once, disappearing inside his head.

There was a gasp from the front of the room. Harry blinked and shook himself. He felt like he had just surfaced from a nightmare and woken back into reality.

The Doctor was grinding the heels of his hands into his temples, as though he had suddenly been seized by a severe headache. His jaw was clenched tight, and his eyes were screwed shut tightly.

"Um…Professor?" Harry asked tentatively. After a few seconds, the Doctor opened his eyes and locked gazes with Harry. The Doctor smiled in an obviously forced and pained manner.

"Yes, Harry?" he forced past his gritted teeth. "What do you need?"

"…Are you all right?" Harry asked after a pause.

"Never better," the Doctor said quickly, his voice rising in pitch. He shut his eyes again for a moment, and then opened them again.

"I think that's enough testing for today," the Doctor said. His breath hitched in his throat. "Pass…pass your papers up to the front."

The whole class looked confused and worried as they brought their roles of parchment up to the Doctor's desk.

"Thank you, thank you…" the Doctor muttered as each person laid down their scroll. "Class dismissed."

With one last worried look at the Doctor, who was covering his face with his hands now, Harry and Ron hurried out the door.

"What's the matter with _him_?" Ron started to say as he and Harry walked down the hallway. Harry wasn't listening, however. The Voice had started to speak inside his head again.

_Why, look who is back, my dear! You weren't expecting this, were you? Come out and play, my friend._

_Ah, it's just a little pain. It will all go away with death._

_Kill you _now?_ No, no, it is too soon. I have uses for you yet. And either way, it would require far too much power to kill such a magnificent creature as yourself from this great a distance. _

_I said I could not kill you. That does not mean I do not have enough power to do…THIS!_

_Good night, my friend! Sleep well! Until we meet again!_

"…like I was telling Lav, it's not what you know, it's _who_…hey, Harry, are you okay?"

Harry had suddenly jerked as what felt like an arc of electricity raced through him. He staggered as his knees gave out from underneath him.

"Harry!" Ron said, alarmed. He just managed to catch Harry by the arms before he fell to the floor.

"Harry, what's wrong?" Ron repeated, panic evident in his voice.

"Nothing, it's nothing," Harry murmured as he tried to push away Ron's hands.

"Don't tell me that's nothing, you just collapsed on me!" Ron said indignantly.

"I'm just tired, that's all," Harry said evasively. "Not enough sleep, you know, with homework and…things."

Ron looked suspiciously at him. "If you say so," he finally said.

"_Won-Won!_" squealed a voice from behind them. A pair of skinny pale arms flung themselves around Ron's neck.

"Hello, Lavender," Ron said, his face a little red. Harry raised an eyebrow at him.

"Well, don't let me keep you two," Harry said, edging away as Lavender coyly drew quite close to Ron.

"Sure, Harry," Ron said. There was a very slight miserable tone to his voice.

Harry backed away quite quickly when Lavender began to settle herself into Ron's lap. He had something a little more important to worry about at the moment than Ron's problems with his girlfriend. For one thing, he was now positive that the voice he kept hearing in his head was threatening the Doctor into doing…something.

And that made him more dangerous than ever.

…

The Doctor knew that he was in trouble the moment the first demon slipped inside his head.

He had been grading papers as his last class took their last tests before the holidays. Some of the essays had been quite good, while others had been…lacking. He was especially disturbed by the lip-shaped smears of lipstick he had found all over Lavender Brown's essay.

Everything had been running smoothly. Then, without a single warning, his mind had been brutally assaulted by a dark…presence. As soon as the 'thing' had attacked, he had thrown up his strongest mental barriers in a split second. He had felt more and more of the assaults as the dark winds crowded into his head, prowling around the iron walls of his last shelter, looking for chinks in the armor.

He had responded to Harry and the rest of the class as well as he could. He could only spare the smallest part of his brain to regular motor functions as he battled furiously with the demons, just long enough for the last students to close the door as they scurried away.

The moment the door was shut, the Doctor fell to his knees, his hands gripping the sides of his head as though that would make the invaders leave him alone. The sheer number of minds inside his head, all working viciously to tear down his barriers, was beginning to overcome him. He panted heavily as they tore at his mind, leaving invisible scars behind them. He fell onto his side as black spots started to blur his vision. His thoughts were becoming disjointed, less focused, weaker…

There was a sweeping sensation inside his head, and the demons were suddenly banished. Chest heaving, he let his head fall back onto the ground with his eyes closed.

The relief didn't last long as a voice like nails on a chalkboard began to speak inside his head.

_Why, look who is back, my dear! You weren't expecting this, were you? Come out and play, my friend._

Groaning, the Doctor shook his head. He wasn't going to lower his barriers just because some insane creature told him to.

_What did you do to me? _the Doctor demanded from behind his barriers as he continued to tremble.

_Ah, it's just a little pain. It will all go away with death._

Startled, the Doctor felt like he'd just been punched in the gut. _Death? You can't kill me. It's going to take a lot more than just a mental attack…_

_Kill you _now?_ No, no, it is too soon. I have uses for you yet. And either way, it would require far too much power to kill such a magnificent creature as yourself from this great a distance. _

The Doctor continued to lurk behind the iron walls. _Is that supposed to be comforting?_

_I said I could not kill you. That does not mean I do not have enough power to do…THIS!_

A burst of white hot pain suddenly erupted inside the Doctor. His breath was completely stolen away as fire coursed through his whole body. He was so surprised he couldn't even cry out as he shook and fought against the knives forcing their way through his veins and cutting him to shreds.

The Doctor screamed inside his head. Only a dark chuckle of sick pleasure answered him. The knives continued to coarse through him, while fire blazed inside right behind them. The Doctor could feel his physical body weakening by the second. Each moment that passed was dragged out for a year, and when the force gripping him finally relaxed its hold, he couldn't muster enough energy to even lift his eyelids again, much less pull himself to his feet.

He could hear the screeching voice faintly through the blood pounding in his ears…

_Good night, my friend! Sleep well! Until we meet again!_

Then the force reached back into his head and, with a faint snapping sound, sent him spiraling into the darkness as he passed out.

**A/N :) Okay…maybe _I _was the one chuckling with sick pleasure as I wrote this chapter…goodness gracious, what is WRONG with me? ;)**

**Bonus points to any reviewers who catch my reference to the Hitchhiker's Guide to the Galaxy! :D**


	13. Chapter 13

**A/N Sorry the chapter's a bit late, our school musical had its last productions this weekend which meant my free time was 0. Bonus points to everyone who caught that the HGttG reference was the star name Babel Fis 42 on Harry's test. :)**

**To clear up any confusion, this story spans from the beginning of ****Half Blood Prince ****all the way through to the end of ****Deathly Hallows****. So, really, the story's not even half way done yet. That can be a good thing or a bad thing, depending on how much you like the story. :)**

CHAPTER THIRTEEN

The first thing that the Doctor was aware of when he came to was the fierce pounding inside his skull. The second thing he noticed was that whoever had been inside his head was definitely gone, and his mental barriers were still intact.

The Doctor's eyelids felt so heavy that it was quite a struggle for him to finally pull them open. Wincing slightly at the light that flooded in, he managed to get his eyes to cooperate long enough for him to determine where he was. He seemed to be lying on his side on the cold stone floor of his classroom. So he hadn't been captured or something while he had been out…

Groaning slightly as the aching pain in his head seemed to peak, the Doctor could barely find the strength to drag himself up into a sitting position. His whole body seemed to have tripled in weight.

Strange…he hadn't _regenerated,_ had he? Slightly panicked, the Doctor raised his hands to feel himself. Same bad skin, same crest of brown hair, same skinny body. The Doctor relaxed and let his hands fall back onto his legs. The…thing inside his head hadn't forced him into regeneration. Good – he didn't have many left, and he didn't want to waste them.

The reality of his situation finally came crashing down on the Doctor. He admitted it to himself – he was a bit frightened that some being somewhere in the universe had the ability to enter his head at will and, apparently, activate his neural pain sensors and…for lack of better words…turn him 'off' for a short period of time.

Exhaling sharply, the Doctor managed to haul himself to his feet using the corner of his desk for support. Shakily releasing the edge of the desk, his knees buckled and he would have fallen over if he had not grabbed the table again instinctively. As he grasped the wood for support, the Doctor noticed a paper tied with a lilac ribbon that he had knocked off the table. Crouching over and still holding the desk with one hand to steady him, the Doctor picked up the piece of paper and untied the ribbon. If he had had the energy, the Doctor would have reached for his glasses in his coat pocket. Instead, he just squinted to make out the flowery print.

_Dear Friend! You Have Been Cordially Invited To:_

_Horace Slughorn's Christmas Celebration!_

_When: The Last Day of Classes at 7:00!_

_Where: Professor Slughorn's Office!_

_Who: Yourself and ONE (!) Friend!_

_WEAR YOUR NICEST DRESS ROBES!_

The Doctor stared at the invitation a lot longer than he normally would have. When had he been invited…? Oh, he remembered, it was a week or so ago, when he had gone to Hogsmeade.

The Doctor considered not going to the "Christmas Celebration". After all, from what Slughorn had told him, there were going to be quite a lot of Slughorn's students at the party, and the odds were not in his favor for him not meeting up with one of his own students there. He could tell that he had probably scared them all during his…episode during class, and he wasn't quite sure how he was going to explain everything to them without telling the truth.

On the other hand, _not_ going might be even worse for his reputation. He had a feeling that Slughorn was going to be looking for him at the party, and if he didn't show up, Slughorn was going to ask awkward questions that he didn't know how to answer. It might also give the impression that there was something seriously wrong with him to the students, and then they would tell the other teachers, and then there would be _more _questions…

As if people weren't suspicious of him already…

After deliberating between the pros and cons of going to the party, the Doctor finally reached a conclusion. He would go. He didn't want to seem suspicious, and, to be honest, a party might be a nice break from everything going on at the moment.

Really, it was just a party. What could possibly go wrong?

…

The Doctor adjusted the bowtie on his suit. He had no idea what "dress robes" were, but he really hoped they were the "Muggle" equivalent of a nice suit.

The Doctor remembered the last time he had worn this suit; he had gone to see the "de-aging miracle machine" with Martha. That was the first time he had met her family…though he had seen plenty of them later that year…

Closing his eyes and willing the memories of the Year that Never Was to recede, the Doctor took a second to compose himself. He was going to a party, he was going to have a good time, and he wasn't going to dredge up any ghosts of the past.

Taking a deep breath, the Doctor pushed open one of the wide doors of Slughorn's "office".

There was no doubt about it; Slughorn's office was _much _bigger and fancier than it appeared to be on the outside.

_It's bigger on the inside,_ the Doctor thought to himself with a small smile.

The office was decorated with giant floating red lanterns that glowed warmly with candle light. Tinsel was strewn about, and a roaring fire kept the room nice and toasty. There were students dressed as waiters milling about with trays burdened with appetizers and drinks. The rest of the guests were clustered together in small groups, all engaged in conversation. A band was playing in the corner, where some students and a few adults were dancing together. The Doctor even saw a photographer mingling with the guests, occasionally snapping a photo or two.

The booming voice behind him took the Doctor by surprise. "Doctor! You made it!"

The Doctor turned around to see the rotund figure of Horace Slughorn and another tall, reedy man approaching him. The Doctor did his best to smile as Slughorn crushed his fingers in a surprisingly strong handshake. "Hello, Horace."

"Good to see you, good to see you…ah! I haven't introduced my good friend, Dilbert Watson. Dilbert here is the Head of the Muggle Relations Department at the Ministry of Magic."

"How do you do, I'm the Doctor," the Doctor said, reaching out to shake Dilbert Watson's hand. Dilbert shook his hand firmly.

"The Doctor, eh?" Dilbert said. "Interesting name."

"Yes, well, my parents never did like to fit in with the crowd," the Doctor said with a smile. This was not, strictly speaking, true, but the truth would have taken a lot of explaining that he really didn't want to do.

"Dilbert, I think you'd like to know, but the Doctor here is actually a muggle," Slughorn said. Dilbert raised his eyebrows in an interested way.

"Really? Why doesn't the Ministry know about this?"

"Oh, er, I'm kind of…new," the Doctor said quickly. Best to stay away from questions.

"New?"

"I've been the Astronomy teacher ever since the old professor…erm…left."

"I see…and, forgive me for asking, but…do you have any idea how you can actually _see_ the castle? I thought that Hogwarts was protected by an Anti-Muggle Perception charm…"

"Oh…" The Doctor thought quickly. What would a regular human say? "Maybe I have a highly developed sensory perception that enables me to disregard all extraneous filters so I can see…things…for what they…are…" _Aaahh, too complicated…_

"I see…" Dilbert said again, though from the look on his face, he didn't 'see' at all. Thankfully, he didn't seem to want to pursue the matter any further.

"Oh, the Doctor here is a bright young chap," Slughorn said with a grin. "I can't understand a _word_ he says, but that's muggle talk for you…no offense, Doctor…" Slughorn took a deep drink out of the glass he was holding and hiccupped.

"So…going home for the holidays, then, Doctor?" Dilbert asked, seemingly keen on changing the subject. "Going to visit some family?"

"Nah, I don't have any family, just me," the Doctor said, shrugging his shoulders in a nonchalant fashion.

"Ah, what a shame. You could still visit friends…"

"I'm staying here for Christmas. And yourself?"

"My wife and I are spending it together, and our son might pop by on Christmas Day…"

"Dilbert! Look! It's Madame Lucille and Lady Beatrice! We simply must say hello to them…good seeing you, Doctor…" Slughorn said as he grabbed Dilbert's arm and yanked him away.

"…Goodbye?" the Doctor said, a bit surprised by the abrupt departure. He shrugged and walked away from a group of seventh-year students that had been drifting closer while he had been talking to Dilbert and Horace.

A waiter passed by, holding a tray of tall glasses filled with mead.

"Don't mind if I do," the Doctor murmured as he swiped a glass off the tray just as the waiter whizzed by.

A series of poorly concealed whispers behind him made the Doctor turn around. A group of his Gryffindor sixth years were talking in not very quiet tones behind their hands. As soon as he turned around, they all became silent, leaving no doubt in the Doctor's mind that they were talking about him. Raising his eyebrows and giving the girls a pointed stare, he again moved away. As soon as they thought he was out of earshot, the whispers started up again. No matter, there were more important things in the universe…or, apparently, the multi-verse…to worry about.

The Doctor's mind was so disconnected from his actually physical movements that he ran straight into a mane of wild, frizzy blond hair.

"Oh, excuse me…" he started to say, when the woman he had run into spun around. She was wearing a number of colorful shawls draped dramatically around her shoulders, and had on a necklace that seemed to be made of mirrors, giving her the likeliness of an exotic beetle.

"Doctor!" the woman said with a hiccup. A whiff of what smelled suspiciously like cooking sherry hit the Doctor in the face.

"Erm…sorry, remind me of your name…?"

"Ah, yes, I sometimes forget that not everyone posses the Sight that I do…Trelawney, my dear, Sybil Trelawney, Professor of the fine art of Divination…"

"Oh…all righty then…nice to see you, I should just be going-"

"Hello," said a wispy, dreamy voice from behind Professor Trelawney. Peering from around Trelawney's massive hair, the Doctor cringed when he saw that it was Luna Lovegood, Hermione Granger, and Harry Potter. Luna and Hermione, he didn't mind, but he would really rather avoid Harry…because Harry had had questions about him right from the start…

"Good evening, my dear," Professor Trelawney said. She squinted at Luna, as though she was having trouble bringing her into focus. From the way Harry wrinkled his nose, the Doctor could tell that he had smelled the sherry as well.

Luna and Trelawney were engaged in a conversation about Trelawney's Divination classes, and Hermione and Harry were quickly whispering together about some topic or another. None of them seemed to have noticed Doctor, so he started to edge away quickly…maybe he could get away without being missed…

"Doctor!" Trelawney half shouted, throwing an arm out and dragging him back. "Have you met my…hic!...friend Luna?"

The Doctor gave a forced smile as he was pulled right into the middle of all the conversation. "Yes, we've met," he said.

Hermione had disappeared. Harry blinked as the Doctor was pulled into view.

"Evening, Harry," the Doctor muttered.

"Evening, Professor," Harry said. "Er…sir, I was wondering, during class this afternoon…"

"It was a migraine," the Doctor lied quickly. "I've been…having them for a while."

"That's not what I-" Harry started to say, but Professor Trelawney cut him off.

"Harry Potter!" she said, in a deep, slightly drunken voice.

"Oh, hello," Harry said unenthusiastically.

"My dear boy!" she said in a very carrying whisper. "The rumors! The stories! 'The Chosen One'! Of course, I have known for a very long time….The omens were never good, Harry…for you _and_ the Doctor here…such _darkness_ I have seen in his past and your future…"

Harry blinked. "Excuse me?"

"Heh heh…what on _earth_ do you mean, Sybil?" the Doctor laughed weakly, trying to divert Harry's attention.

Trelawney continued on as if she had not heard either of them. "But why have you not returned to Divination, Harry? For you, of all people, the subject is of utmost importance!"

"Ah, Sybil, we all think our subject's most important!" said a loud voice, and Slughorn appeared at Trelawney's other side, clutching a glass of mead and an enormous mince pie. The Doctor could not think of anyone he would rather see less at the moment, but Slughorn didn't seem to sense the awkwardness of the situation.

"But I don't think I've ever known such a natural at Potions as Mister Potter here!" Slughorn said. "Why even Severus-"

To the Doctor's horror, Slughorn threw out an arm and seemed to scoop Snape out of thing air toward them.

"Stop skulking and come and join us, Severus!"

The Doctor revised his previous statement. Slughorn had found someone he would rather see less: Snape. Both Harry and the Doctor grimaced and stared awkwardly at the floor as Snape joined them.

The conversation continued for a while, while the Doctor remained staring steadfastly at the floor, determined not to look up for fear of being forced to join in the talking.

There was suddenly a scuffling sound that made the Doctor finally look up. Argus Filch was dragging Draco Malfoy into the room by his ear.

"Professor Slughorn," wheezed Filch, "I discovered this boy lurking in an upstairs corridor. He claims to have been invited to your party and was delayed in setting out. Did you issue him with an invitation?"

Malfoy pulled free of Filch's grip, looking furious.

"All right, I wasn't invited!" he said angrily. "I was trying to gatecrash, happy?"

"No, I'm not!" said Filch, a statement at complete odds with the glee on his face. "You're in trouble, you are! Didn't the headmaster say that nighttime prowling's out, unless you've got permission, didn't he, eh?"

"That's all right, Argus, that's all right," said Slughorn, waving a hand. "It's Christmas, and it's not a crime to want to come to a party. Just this once, we'll forget any punishment; you may stay, Draco."

The Doctor wasn't particularly interested in this turn of events; the more fascinating sideshow involved the people standing around him. Only Filch's face was predictable; outraged disappointment. Draco, however, looked equally unhappy by Slughorn's verdict. Snape was looking at Malfoy as though both angry and apprehensive. Harry had a look of deep concentration…he had obviously noticed the side show as well.

As the Doctor watched silently, Harry continued to scrutinize Draco's face. He seemed to be just as puzzled by Draco's odd reaction as the Doctor was…

"I'd like a word, Draco," said Snape suddenly.

_Oh ho,_ the Doctor thought. _Now _this _is interesting…_

"Oh, now, Severus, it's Christmas, don't be too hard – "

"I'm his Head of House, and I shall decide how hard, or otherwise, to be. Follow me, Draco." With a swish of his long black cloak, Snape and Malfoy disappeared out of Slughorn's office.

The Doctor took a quick glance at Harry. Shuffling feet, shifting glance between Luna and the door, excessive blinking…he was going to follow Snape.

"I'll be back in a bit, Luna – er – bathroom."

_So you're going to do a little recon, eh, Harry?_ The Doctor thought, while fingering the perception filter hidden underneath his coat jacket. _Well, two can play that game…_

Moving away from Trelawney and Luna, the Doctor activated the perception filter, and with a quiet whirr, it clicked on and he turned 'invisible'. Then, careful not to tread on anyone's feet lest he give away his position, the Doctor snuck out the door after Harry, Malfoy, and Snape.

…

Harry did his best to breath quietly as he moved out into the deserted hallway, in case Malfoy and Snape were nearby and could hear him. He pulled the Invisibility Cloak out of his pocket and was about to pull it on.

The voice behind him made him jump about half a meter into the air.

"Going somewhere, Harry?"

Spinning around, the cloak still clutched in one had, Harry almost had a heart attack when he saw the Doctor standing right behind him.

"…Doctor?" Harry spluttered. "But…how…?"

"So what's this, then?" the Doctor said, running one of his hands through the cloak's silvery fabric. "A molecular scrambler integrated _into _the cloth? Oh, that's clever, wish I'd thought of that…"

"Sir?" Harry asked, confused as usual when it came to the Doctor.

"Never mind, never mind, just put it on," the Doctor said, throwing the cloak over Harry and watching as he vanished.

"Veeeeery good," the Doctor said slowly. "Oh, that is beautiful. I can't see you at all!"

Harry stood there awkwardly for another moment. "Uh…"

"What are you still doing here? You're going to lose them!" the Doctor said indignantly.

"I…what?"

"Snape and Malfoy, of course."

"And…you aren't going to stop me following them, sir?"

"Of course not! You should have seen _me_ at the academy…never mind that, get going! They went that way." The Doctor pointed off down a corridor to the left.

Harry turned to look, and when he turned back around, he was again surprised to see that the Doctor had vanished.

Raising an eyebrow under the cloak, Harry nevertheless set off down the hallway.

Malfoy and Snape were conversing in hushed tones inside a deserted classroom. Harry listened as closely as he could. Mistakes…an Unbreakable vow…and…what was _that?_

A crackle of energy, rather like static on a television, appeared in the corner. Harry was shocked to see the dim form of the Doctor hunched over a few feet away, listening through the wall.

"Blasted thing…" he heard the Doctor mutter. The Doctor hit his waist, and he suddenly disappeared again.

Almost too distracted to keep listening, Harry barely caught the end of Snape and Malfoy's conversation, which was more than enough to make him extremely confused and set his mind racing.

_What is going on?_ Harry thought desperately, not for the first time that year.

**A/N There was a Hunger Games reference Try to find it! More bonus points XD**


	14. Chapter 14

**A/N: lol two years later and people still read this **

CHAPTER 14

It was the first day of winter holidays, and the castle was _his. _

Almost every student had gone home for the break. Parents apparently were very concerned about this 'Voldemort' fellow and wanted to keep an eye on their children. The Doctor planned to take full advantage of this fact. His screwdriver was waiting in his pocket. He had his molecular scrambler/perception filter prepped and ready for use at any second. He was even wearing his favorite (and almost assuredly lucky) pair of Converse. He was prepared for anything. Or so he thought.

Investigating without hundreds of children underfoot started out as a very welcome change. He could comb the library and the hallways in complete silence. Concentrating was a much simpler task. However, the Doctor was, by his nature, an extremely social creature. And when he was left alone for extended periods of time...well. Accidents tended to happen.

It was Christmas Eve and the Doctor was wandering the hallways after a thoroughly unproductive research session under the batty librarian's watchful gaze. Madame Pince was extremely protective over her precious tomes, and spent the entire evening hovering over the Doctor's shoulder. It seemed to the Doctor she was convinced a Muggle like himself could simply not be trusted with the fragile books. The Doctor's cheeky comment about his personal belief that "books were the best weapons in the world" had sent her into a frenzied panic and got him kicked straight out of the library.

Not that he couldn't easily sneak back in after everyone had gone to bed. Still, it was the principle of the thing.

The Doctor was exploring Hogwarts' upper levels. During his first semester as a teacher he had pretty much discovered all he could about the bottom floors of the school. Which was very little, but still. Finding an excuse for being on the top floors had proven more difficult than the lower levels, so he planned to find out as much as possible while everyone was gone and he never had to explain what he was doing.

The tall arches and complex tapestries decorating the seventh level were well and good, the Doctor thought, but not exactly helpful in the slightest.

"Now, if I had just the tiniest bit of technology available, the situation might be different," the Doctor informed two empty suits of armor guarding a blank wall. "Anything, really, from my universe would be helpful at this point."

Unsurprisingly, the suits of armor didn't respond.

"Anything from my universe, I tell you. Anything," the Doctor half-sighed as a strange feeling of wistful nostalgia seized him for a moment.

A clicking noise, and a huge door slowly appeared between the two suits of armor.

"...What."

The suits remained impassive.

The Doctor glanced to his left and right. "Is this some sort of wizard prank? Because let me tell you, I've come across some very funny pranks in my time, I spent a full month on Natilan-6 during their Festival of Humor and saw more Natilian underwear flown from flagpoles than I care to admit..."

The Doctor trailed off as his voice echoed off empty halls. "Not a prank then?" he asked. "Good. I expect better from the wizard pranking community."

The heavy wooden doors seemed to be waiting expectantly for him. Their sudden appearance and their aura of mystery twisted something in the Doctor's stomach. He took one circular handle in each hand. "Allons-y!" he said with a false grin and a giddiness he didn't feel, and threw open the doors.

A blast of chilled air hit him full on and curled out of the room in visible waves. A shudder (from the cold? Or something else?) spread across his spine. With an unexplained hesitancy, the Doctor stepped into the room.

The room was lined with glass boxes of varying sizes, some only a meter tall, others towering high over the Doctor's head. They were each covered in a layer of frosty crystals. The room was almost literally freezing, and was apparently even colder inside the boxes. The only source of light in the room came from a line of white LED lights installed along the top and bottom of each box.

Wait...LED lights?

"Is that electricity I spy?" The Doctor grinned, ominous premonitions forgotten in light of the...lights. Of course, the moment he moved out of the doorframe and fully into the room to look at the bulbs, the doors swung shut behind him with a resounding slam.

"You're kidding me!" the Doctor groaned, testing the doors and unsurprisingly finding them locked. "No, this is too obvious. This is so entirely cliché that the 'overdone' factor has spun all 360 degrees around and become an original idea again."

The doors maintained their annoying habit of remaining silent, even after the Doctor employed a few imaginative Gallifreyan swears that surely had his mother spinning in her grave and he kicked them for good measure. This only resulted in a sore toe instead of relenting hinges.

"How many times, Doctor," he said, sitting on the floor and nursing his throbbing toe, "how many times have you regretted not having a wood setting on your screwdriver? How many times have you resolved to add a wood setting? How many times is it going to take?" Frustrated, he reached to the nearest glass box and rubbed away the frost so he could see the lights inside. "You little buggers had better be worth..."

There were seventeen bright lights inside the box. There were also two large metal feet.

"You've _got_ to be joking," the Doctor said as he slowly stood and wiped away the top of the glass, only to find himself staring into the soulless eyes of a Cyberman.

The Doctor jumped backwards, but the cyberman didn't activate or attack him. A quick scan with the sonic screwdriver revealed that the interior of the box was well below freezing, and even though the cyberman was giving off life signs, it was in a sort of "shut down" mode.

"You're being preserved then," the Doctor said to the robot man. "Though I can't think of any reason whysomeone would keep you _here_ of all places."

There were hundreds of other boxes in the room. "You can't all be cybermen," the Doctor murmured to himself. A scan of the area showed life signs from some boxes and nothing from others, but as of yet nothing seemed to have reacted to his presence. The Doctor went from glass case to glass case, wiping away the ice. He found two more cybermen, some Sontarans, a couple of Hath, a Saturnynian, a Tivolis...

"This is the most _random_ assortment I've ever seen," the Doctor said as he wiped a box and found an ion ray gun. "Where did you all come from? I know I said I wanted anything from my universe, but this isn't quite what I had in mind."

He was interrupted by the sound of shattering glass behind him.

The Doctor whirled around with his screwdriver held high in the air.

"Hello?" he called out. A few rows of boxes away he could see that the front of one box had been smashed open.

From the _inside._

"I'm not going to hurt you," the Doctor said to the empty room. Or at least the formerly empty room. "Just come on out and we can talk, all right?"

While he said this, a surreptitious click of the sonic screwdriver confirmed that the temperature inside each box was rising. The preserved creatures must be waking up…

Some sixth sense started tingling in the back of his neck. "Who's there?" he started to say.

He found himself face to face with the snarling face of a Weeping Angel, her outstretched finger just millimeters from his throat.

"_Rassilon!_" he shouted in surprise, stumbling backwards and tripping over his own feet. The angel's contorted look of fury seemed to follow him to the floor.

Another crash, and the tinkle of falling glass shards. The Doctor instinctively looked towards the sound for an instant. It was enough time for the angel to appear at his side, crouched over him with her hand hovering over his chest.

"Nope, nope nope nope," the Doctor said, wiggling out from underneath her and barely avoiding touching the stone fingers. "I have papers left to grade, so this is going to have to wait for another time, I'm sure you understand," he babbled, never letting his eyes drop from the frozen figure.

He caught a flicker of movement out of the corner of his eye.

"Two of you?" he groaned, senses on high alert for the second angel.

A third box smashed open somewhere he couldn't see.

"Three of you. Perfect."

Hesitantly backing away and keeping the crouched angel directly in his line of sight, he ducked between two tall cases.

He could almost hear the crackle of flesh turning to stone as the second angel thrust her arm into his hiding place.

"Oh, _hell_ –" he stuttered as his hearts instantly started pounding faster. He squeezed out the other side not blocked by a Weeping Angel and looked for the door in his peripheral vision.

The third angel was standing directly in front of the door, her stone hands wrapped tightly around the handles. The Doctor backed up as far as he could to try and keep all three angels somewhat in his sights.

The Doctor bumped into one of the cases and to his horror, he blinked. In an instant, all three angels had vanished.

"No, no, no!" the Doctor said, a slightly panicked tone coloring his voice. He pressed his back to the case so he could avoid an attack from behind.

Before he had time to even think, a box at one end of the room was toppled over, shattering on the ground and setting off a domino chain of falling glass cases. He barely made it out of the way before the case behind him fell and crushed him. He landed heavily on the piles of cutting shards, slicing open his palms.

Instantly an angel appeared to his left, kneeling on the ground with her wings flared and her tongue pointing out of her teeth like a snake's.

The Doctor gasped and scooted away. The other two angels had pushed over more rows of boxes. The deafening sound and glinting light of crashing glass made concentrating on the angels impossible.

There was a gust of wind as an angel tried to swoop past him that sent a wave of glass shards at him face. Only sheer luck prevented him from being blinded. More stinging cuts opened on his cheeks.

_Of course they're trying to blind me, if I'm blind, I'm helpless! _The Doctor thought frantically. The third angel appeared to his right, her hands stretched towards his eyes.

The angels were closing in. The flickering lights from the destroyed boxes allowed them to inch forward, their hands and wings reaching for him.

"I recognize the irony of course," he said in a strained attempt at nonchalance. "I said I would just _love _to see anything from my universe…"

His back hit the wall, and he couldn't move without taking his eyes off the angels.

"…and here you are. My _favorite_ killers."

For the moment he had them frozen, but he couldn't keep his eyes open forever.

"You see, the question I have isn't so much how you're here as it is _why _you're here. Though I wouldn't say no to an explanation of how either, now that I think about it." A plan, a plan, he needed a plan.

"Are the people in those other boxes dead? I'm assuming my being here triggered them to start waking you lot up. I can't imagine having their life support cut off is doing much good, hmm?"

The angels were cutting the power to the lights, and a brief moment of darkness let them slip in even closer. The Doctor was forced to crouch on the floor to avoid touching them.

"Now, if you send me back in time, I'm genuinely curious about where I would go," the Doctor said, still rambling. His eyes were beginning to water and his hearts were practically leaping out of his chest. "I don't know any of the history of this universe, you see, and while the learning experience would certainly be _fascinating_, I'm sure it's nothing I can't find out from a history book."

The flickering lights reflected off the stone veneer of the angels, making them look wet and scaly. Their pointed teeth gleamed just centimeters away from the Doctor's skin. His eyelids were twitching, he was going to _blink_…

And out of nowhere, he heard a _meow_.

Startled, the Doctor looked between the angels and saw a fluffy, black and brown cat sitting on its haunches in front of the door. Its round reflective eyes were fixed squarely on the three angels.

He was _saved_.

The Doctor let out a huge sigh of relief. "Now, don't stop looking at them, you understand?"

The cat couldn't answer in words, but it mentally projected a sense of understanding.

The Doctor delicately slid out from underneath the claw-like fingers of the angels and stood up, before promptly getting his feet tangled and tripping onto the sparking remains of some machine lying in the crushed remains of its glass container. He couldn't tell what it was in the dim lighting, but he scooped it up anyway. If he got his hands on some tech from his own universe, then maybe the night wouldn't have been such a waste after all…

The cat let out a frustrated hiss and the idea to "_hurry up!_"

"Coming, coming," the Doctor said as he scrambled to his feet and to the door. To his surprise, the door was no longer locked and was now sporting a cat flap, as though the room knew he needed to escape.

His eyes again trained on the angels, the Doctor opened the door behind him and slowly backed out of the room. The cat brushed past his ankles and back into the hallway. The Doctor eased the door closed, his gaze never wavering from the statues in the corner of the room, and then quickly slammed it shut.

All the tension drained out of the Doctor and he slid to the floor, still clutching his pile of machinery. The cat gave him a disapproving glance and began to lick her paws haughtily.

The Doctor chose to ignore her attitude and gave her an affectionate scratch behind the ears. "You clever old thing," he said with a smile. "How did you know to find me?"

The cat twitched under his hand distastefully, but sent a feeling of "heard you".

The Doctor nodded. "I see…must've been projecting a call for help without meaning to."

A thumping pair of footsteps came from around the corner. Argus Filch, the caretaker, appeared with his lantern held high. "Mrs. Norris?" he said in a scratchy voice. "Where did you get off to?"

The light from the lantern fell across the Doctor and the cat. Filch scowled when he saw the Doctor petting the cat's fur.

"What d'you think you're doing with my cat?" he asked angrily as Mrs. Norris sprang from the Doctor's side and into her owner's arms. "Trying to kidnap her? Play funny Muggle games with her head?"

"What? No, of course not, I was just – "

"Hmph! Looks like she put up a fight, anyways." Filch pointed to the scratches decorating the Doctor's face and hands. "My Mrs. Norris won't put up with your Muggle antics," he practically spat at the Doctor.

"No, I was just…" the Doctor was too tired to argue. "I just found your cat, that's all."

"Oh, I'm sure," Filch snarled. "You're nothing but trouble, you are. Mark my words, you'll cause nothing but problems for us here!"

"…I'm sorry? I guess?"

Filch growled. "You stay away from me and my cat!" he said, before storming off, his lantern light sending shadows swirling on the walls.

"Gladly," the Doctor grumbled, picking at the wires in his lap.

**A/N So I guess I'm doing this again. Thanks so much for all the reviews people sent over the years, they were all very kind. I (obviously) took a break from writing for a while and all your helpful comments are pretty much what inspired me to pick this up again. So hopefully updates will become a somewhat regular thing. I can't promise a new chapter every week, but I can say there won't be any more two-year hiatuses. Cross my heart. :)**


	15. Chapter 15

CHAPTER 15

The Doctor beamed as his sixth year students streamed into the classroom. "Welcome back, welcome back everyone. Had a good holiday? Ready to get back to work? Good, good..."

Harry and Ron sat down next to each other at a desk near the front of the room. There was a large new object covered by a white tarp sitting on a table next to the classroom's customary telescopes. The Doctor was hovering protectively by it, never straying more than a meter away as he greeted his students.

"That's gonna be some other muggle gimmick I'm not gonna understand, isn't it?" Ron mumbled miserably, not at all excited to be back at school. Harry patted his arm sympathetically.

After everyone had settled down, the Doctor gestured towards the mysterious tarp. "So I suppose you're all wondering what it is that I've got here?" There were a few murmurs of agreement around the classroom. The Doctor's infectious smile grew, if possible, wider. With a dramatic sweep of his arm, he flung the tarp away to reveal...something.

"Isn't it beautiful?" the Doctor asked. Harry wasn't sure he would describe the thing as beautiful, per say. It certainly was intriguing, to say the least. The main part of the...object was a tangle of wires supported by what looked like homemade black casing. A large tape recording device was mounted on the front, and a duct taped satellite receiver protruded from the top. One wire led away from the device and was hooked up to the Doctor's metal wand screwdriver thing, which was flashing blue periodically.

Before anyone could ask the obvious question, the Doctor continued. "This is what's known as a radio telescope. It's used to pick up cosmic microwave background radiation, or CMBR. Now, in this day and age, these things usually need to be...oh, say fifty or sixty meters to pick up the kind of radiation we're looking for. However..." the Doctor picked up his screwdriver, which was still pulsing blue. "I've made a few modifications with my screwdriver here and am amping up this beauty's power by quite a bit. This kind of tech won't be available in the, ah, muggle world for another couple of decades, so surprise! You lot get the first sneak peek."

"What is he talking about?" Ron mumbled, then buried his head in his arms.

Harry raised his hand on Ron's behalf. "Excuse me, professor, but what is, um, cosmic background...whatever?" He chose to ignore the Doctor's bizarre statements about the 'future', knowing full well he wouldn't get a straight answer if he asked.

"Well, that's the first topic of today's class, Harry," the Doctor said, pulling the tarp over the radio telescope. "The telescope's been charging for a few days, and I thought it would be ready by today, but it looks like its going to need a few more hours, so we're all going to meet here again tonight at midnight."

Ron groaned with his head still resting on the table.

"Don't worry, Ron, there's no homework tonight other than that, so it's not too bad. Anyway, cosmic microwave background radiation! One of my personal favorite discoveries, mostly because it was made by accident, but that's besides the point." The Doctor paused for a minute to click on his galactic projector and turn all the lights in the room off, so the only light was coming from the projected stars. "Now, tell me, what can you see besides the stars?"

Parvati raised her hand. "Comets? Meteors?"

"Correct, but not what I'm looking for. No, I'm thinking about the space in between the stars. What fills the void between the light? Is it nothing? Yes, Neville?"

Neville lowered his hand. "Um, maybe it just looks like there's nothing? Maybe its, uh, the CMR you mentioned?"

"CMBR, and correct! Good thinking there, Neville. You're right, it looks like there's nothing. To a normal optical telescope, it looks like there's just an empty black stretch that takes up most of the space in, well, space. But if we amp up our radio telescope and start looking for thermal microwave signatures..." The Doctor fiddled with the projector, and an almost imperceptible glow emanated from the black space. "We get CMBR! Now who wants to guess what CMBR actually is? How about you, Seamus?"

"Is it...sort of leftover light?" Seamus guessed.

"Brilliant! What we are actually looking at are light waves that came from the original Big Bang that started the universe. The microwaves are all identical distances apart, and judging by our calculations, they all originated at the same time too, roughly thirteen billion years ago when the universe began. This is the start of your universe, kids! How's _that_ for exciting?"

This got an impressed nod from most of the students. Even Ron had pulled his head up to look at the faintly glowing CMBR. Hermione, unsurprisingly, had more questions.

"Excuse me, professor? You said that all the light should be uniform since it all came from the same place and expanded away at the same rate. But more towards the center it seems notably brighter to me..." Hermione said.

"We-e-ell," the Doctor said, running his hand through his fringe of brown hair and making it stand up in all directions. "That's the tricky bit, isn't it? When I looked at this projection in my own univ-..." the Doctor paused to clear his throat. "Ahem, my own, ah, hometown, everything was definitely at the same level. No problems at all, everything good to go! As soon as I, well, arrived here was when everything decided to become just a bit more complicated."

The Doctor went to the projector and fiddled with some of the dials. The projection zoomed in to the brighter area. "Now, if I change the time and space configurations..." the Doctor muttered. "Aha! Look at that!"

The CMBR glow separated in front of them into two separate layers, one of them faint like the rest of the universe, the other shining significantly brighter.

"Now what do you make of _that?_" the Doctor said with a smile. The students murmured among themselves, but no one could really explain what they were seeing.

The Doctor shook his head. "Nothing? Well, that's all right. I was wrong, Ron, there is a homework assignment: try to think of an explanation for this...phenomenon. Really, any input you have is very, very welcome." The Doctor switched off the projector. The bright universe faded away from the classroom. "Well, that's enough time spent on my own research. Moving on, let's get back to studying orbital paths and their effect on other celestial bodies..."

The rest of the class passed quickly, as did most of the evening. Around eleven o'clock, Harry and Ron were sitting in front of the fire in the common room, parchment, quills, and text books spread all around them. Ron was leaning back against the couch, already nodding off.

"Ron? Ron, wake up," Harry said, prodding him in the ribs. Ron blearily opened his eyes. "Come on, we're working on McGonagall's essay on transfiguring chinchillas into pillows, remember?"

Ron sniffed and nodded. "Yeah, yeah," he mumbled. His head fell forward against his chest again.

"Oh no you don't," Harry said, smacking him in the head with a throw pillow. Ron snorted and jerked awake.

"I'm awake, I'm awake! Bloody hell..."

"What are the long term effects of the transformation if it's not done properly?" Harry said, reading off the paper.

Ron rubbed his eyes. "You get a very angry pillow with weird teeth."

"Ha ha. I'm sure McGonagall will love _that_ as your entire essay." Harry put his quill down. Clearly, he wasn't going to get very far with Ron. "How about the Doctor's homework, that doesn't have anything written. Unless thinking is too much for you now."

"I can _think_ just fine," Ron grumbled. "Okay, I think the reason for our double glowing universe is we've all got double vision from having to concentrate on glowing dots for too long."

"It's like you're begging to get hit," Harry said, once again throwing the pillow into Ron's face. "I think it's because his machine's all messed up by the magic here. That's a thing, right? Hermione said something like that a while ago, I think..."

"Nah, doesn't he magic-proof his room or something?" Ron asked.

"Oh, maybe he does, that would make sense."

Ron yawned and streched. "Let's just agree that if he calls on us for an answer, we say we couldn't think of anything. Because we couldn't."

"Or we could make it up on the spot, we're good at that."

"Use the word 'influx' a lot, he likes to say 'influx'," Ron said as he stood up. "Agh, we've got to get going if we don't want to be late."

Harry reluctantly joined him and they made their way to the astronomy tower, where most of the rest of their class was already waiting.

"Nice of you to join us, boys," the Doctor said, somehow still as chipper as he was in the middle of the day. His arms were full of the radio telescope he had shown them earlier, which looked very heavy but he seemed to be carrying with relative ease. "Now that we're all here, let's head up!"

The night air was crisp and chilled, and Harry fervently wished he'd remembered to bring his scarf and gloves. There wasn't any snow on the ground, but it felt like there should be. The sky was completely clear and the full moon shone brightly on the small group, bathing them in enough moonlight to light up the entire area. The Milky Way stretched brilliantly above their heads.

"Magnificent, isn't it? Nothing quite like star gazing, is there?" the Doctor said with a faint note of nostalgia as they ascended to the roof. "It's been a long time since I've just...watched the stars without, oh, you know, interfering with them."

Harry sighed. "Sometimes you just don't make much sense, professor," he said, too tired to restrain himself.

"I don't make much sense to anyone Harry, myself included," the Doctor said, brushing off Harry's comment. The group assembled around a pedestal mounted in the center of the tower roof. The Doctor dumped the radio telescope onto with a clatter and adjusted the satellite to face west. He clapped his hands together. "All right! So what we're doing tonight is monitoring CMBR, and looking for anything that might be considered out of the ordinary." He pulled a paper out of his coat pocket and showed it to the students. It was a colored thermal graph in the shape of an oval, showing patches of yellow where it was bright and green and blue where there was less energy. An orange stripe through the middle showed the most background radiation.

"This should be appearing on this screen here," the Doctor said, pointing to the screen on the radio telescope. Sure enough, a similar display was projected there. "This is what's considered normal. For the next three hours, we're each going to take a turn watching the screen for any...deviations from normal. When it's not your shift, you are completely welcome to take a nap. Let's start with...Dean. You're up for the first fifteen minutes."

Dean shuffled to the radio telescope while the rest of the class tried to find a comfortable place to rest on the stone floor. The Doctor sat down with his back to the class, his gaze fixed on the sparking heavens overhead. Harry, instead of lying down, decided to sit down next to him. They sat in silence for a while, just watching the stars, before the Doctor finally spoke up.

"So, Harry, what's your hypothesis on this second energy wave?" he asked.

"Er..." Harry stuttered. "Maybe it, um, has to do with another...influx. Of energy." Inwardly, Harry thought that sounded pretty stupid, but the Doctor nodded thoughtfully.

"I was having the same thoughts," he said, still watching the stars. "It's unprecedented, really. I can't think of a single instance in all of history - _all _of history, mind you, Harry - where a second wave of CMBR was recorded. It just doesn't make sense in the universe's timeline. Of course, matters are a bit...well. More complicated here."

"Here in the...wizard world you mean?" Harry asked hesitantly, as always confused by the Doctor's words.

"Yes, and other, ah, things too," the Doctor said. "Either way, it's like the universe started twice! And I've got my own theories about this, of course. This experiment I'm running with you lot is mostly just to confirm what I'm thinking."

Harry didn't really know how to respond to that, so he just nodded.

The Doctor sighed. "It's like this, Harry. When I arrived here at Hogwarts, it clearly required a _lot _of energy to pull it off. A _lot _a lot of energy."

"As in 'restart the universe' a lot of energy?"

"Yeah, like that sort of 'a lot' of energy. Anyway, there's not much I've ever encountered that even scrapes the surface of that kind of power. If what I'm thinking turns out to be correct, it'll narrow down my...research a lot."

"Your research?" Harry asked. "What are you researching?"

"Well..." the Doctor paused. "I did get here under less than normal conditions, as you're well aware."

Harry was still confused. "Didn't you just accidentally step into a cursed phone booth and get transported here?"

"That's...that's sort of it. Well, I say sort of. More like that's the start of the story. Well, it's a bit of the start. Well...it's a considerably simplified version of the smidgen of the start of a highly convoluted story. Well, okay, basically no, that's not it at all. But it's sort of a good way of explaining it."

It was way too early in the morning for Harry to try and process _that_ mess, so he decided not to and just pressed forward. "And so you're researching how you got here. With science."

"Well..."

"Would it be easier if I just told you it was probably magic and save you the trouble?" Harry asked.

The Doctor chuckled. "You're right, it would be easier, but I don't think magic is the answer in this case."

Harry yawned widely, and blinked to clear his bleary vision. The Doctor pushed lightly on his shoulder to get him to lay down. "Go to sleep, Harry," he said. "You need the rest." Harry wanted to protest, but his eyelids were so heavy that he really couldn't, and he drifted off into a doze.

Several hours later, Harry woke to the sound of the Doctor giggling. It took a couple tries for him to focus on the Doctor pouring over the radio telescope next to Neville and make out what he was saying.

"Oh, yes yes yes! Neville, this is _brilliant_. You understand what this means, right? The light from this massive new energy influx has barely had any time to travel at all. Going by my calculations, which are perfect because I'm a _genius_, this energy surge couldn't have happened more than a few months ago, right in this specific area of the universe,_ or_, right when I arrived here. Oh, this is _perfect_! There's hardly anything from my universe that could have pulled me here that has the capability of producing such a _spectacular_ energy spread...Neville, I've got all the pieces of the puzzle right here in front of me, I just have to _figure it out..._"

"Uh-huh, professor..." Neville sounded just as tired as Harry felt.

The Doctor quickly roused everyone on the tower roof. "Wake up, wake up, we're ending early, I've got _everything_ I need, thank you..." The class barely roused itself as they each stumbled back down to the classroom and parted ways to their own dormitories. Harry was relatively sure in his sleep-addled mind that the only reason he made his way back to his room without getting hopelessly lost was through force of habit. When he and Ron finally collapsed on their beds without a word to each other, he didn't have any energy left to ponder the Doctor's odd words, and almost instantly fell asleep.

**A/N So July 16th is the Half-Blood Prince's release anniversary. Happy Birthday, HBP.**


	16. Chapter 16

CHAPTER 16

In retrospect, it should have been obvious to the Doctor. Who else could have operated from the shadows so neatly and completely? Who else could have harnessed the energy required to break down the walls between parallel worlds? Who else despised him enough to go to such great lengths to hide him away from his own universe?

The Doctor was unfortunately surrounded by students in the library when he figured it out. As all the pieces of the puzzle clicked together in his mind, something else switched on as well. One second he was seated comfortably at a small corner table racking his brain for memories of anyone who ever had the power to do this, and the next second he was sprawled on the floor as an incredibly intense psychic assault exploded in his mind. Dimly he was aware of a student - Erwin? Ernie? Elwood? - at his side, mouthing words at him and gesturing to the other students. He was too absorbed in pain and trying to construct mental barriers against the attack to make out what the student was saying to him.

The psychic equivalent of a polite knock tapped at his mental shields. _Are you going to come out, or are you going to do this the hard way? _said the voice, tutting as though dealing with a stubborn child who had locked himself in his room.

_Ha! I was right then, _the Doctor said. _I figured out who you are, so you lash out, as if that could make me forget. _The Doctor snorted, doing his best to think through the frustratingly persistent pain that was circling his hastily constructed barriers and piercing through where it could. _And I also know that this talk and… situation shouldn't be happening. There's no way you can be in my head, it's impossible. _

The voice dropped its mocking tone, turning instead to a growl. _And yet, we are speaking. You forget, Doctor, that I had one second where your TARDIS's soul was mine, and by extension I was connected to your mind as well, no matter how shallowly. _

_Well that's it in a nutshell, isn't it? _the Doctor said, noting with slight distaste that his body was beginning to shudder as it strove against the barely restrained pain. _Shallow connection. You shouldn't have any mental connection at all, though I guess the TARDIS took care of that. What did you do, plant mental _bombs? _This is quite the mental attack for just a shallow connection. _The Doctor felt an impression of a scowl from the voice, and his trembles mounted to near convulsions as the pain somehow became even more intense. Someone seemed to be restraining his thrashing limbs, but he couldn't make out who or what it was.

_It doesn't matter how I am controlling you. The point remains that you are under my power, _the voice said.

_You of all people should know that unless the mind is yours, you can't really control someone. You've always been invested in controlling others' wills. _The Doctor cringed and may have groaned aloud as another wave of piercing mental shards swept across his mind.

_Enough! Yes, Doctor, you may have discovered my identity. But you have not discovered my plans and are at my mercy. I have you locked in a universe where you have no power whatsoever. _I _am still in control of this world, and you cannot stop me. _

_Would it be rude if I brought up that you should be dead? _

"... blink if… hear me… Doctor?"

_I have escaped death before under much less convenient circumstances. _

A distant feeling of weightlessness meant that the Doctor's physical body had been levitated onto a stretcher or a table or something. _I wouldn't call the circumstance 'convenient' exactly..._

_With that sort of power begging to be used, waiting right at my fingertips? Please, Doctor. _

"... not responding… fetch Professor… "

_Even with the power you had, you shouldn't have been able to get into my TARDIS and into my head. _Thinking straight was becoming increasingly difficult as the 'bomb' continued to flare. _Well, with the TARDIS in your control...maybe. But you didn't have the power to reach it before. _

The voice scoffed. _You are obviously intelligent, and yet the simple concept of a stable time loop continues to elude you. It's laughable. I merely went back in time and _gave _myself the power of the TARDIS in order to reach the TARDIS in the first place. _

_That's a paradox, not a time loop. _A less fortified wall began to crumple underneath the onslaught of the mental 'bomb', which the Doctor hastily tried to repair. _That would suggest that the TARDIS's energy was never originally created, and it only exists as a consequence of its own… existence. _

_That would be true, if we were speaking of the TARDIS's creation. However, _and here the voice shoved hard against the toppling wall, destroying it and tearing a gasp of pain out of the Doctor, _we are discussing my ownership of the energy, not its original creation. I was able to use the energy before I had, linearly speaking, given it to myself because essentially, there is no way to truly change the past. I had given the energy to myself in the past all along, as soon as you begin to view time and events in a more circular fashion. _

_Wibbly wobbly timey wimey stuff, you mean, _the Doctor said, exhaustion beginning to wear deeply on his mind. _Is now really the time for an in depth metaphysical discussion… _

Before the voice could respond, both were extremely surprised by the arrival of a third presence, hovering at the very edge of the Doctor's consciousness. _What's this? _it scoffed. _Fraternizing with an accomplice outside of Hogwarts, Doctor?_

_A friend of yours? _The original voice turned the slightest bit of attention away from tormenting the Doctor to investigate the newcomer.

_Snape! _the Doctor shouted, instantly recognizing the oily tone of voice. _Get out of here, it's dangerous - agh! _Another full-fledged assault threw itself against the precarious shields. The Doctor knew he wouldn't be able to hold out much longer. _What are you _doing _here?!_

_You've been having a rather embarrassing fit up there in the physical world, _Snape said. The Doctor could almost see the self-satisfied curl of his lips. _I was sent to… ah… snap you out of it. _

_Well, _clearly,_ that's going to take a little work. _The Doctor groaned again. He was too tired and in too much pain to deal with Snape now…

The voice was projecting an obvious sneer. _Well, Doctor, this has been interesting. Unfortunately, as you have undoubtedly figured out, my abilities tire me quickly. I believe I will leave you here with your… friend. Until next time, when I will finally meet you face to face..._

Another fierce strike of fire and glass, and the Doctor's shields collapsed, taking the Doctor spiraling down into darkness with them.

...

An insistent pounding in his temples brought the first vestiges of awareness. For the first few seconds, the Doctor's drifting awareness could only hear the _thud, thud, thud_ of his heartbeats, doubly loud because of his two hearts thumping in rhythm. Gradually, he began to hear other soft sounds, like the shuffle of feet across the floor and the clink and slosh of two glasses tapping each other. The Doctor lightly curled his fingers around the sheets of the bed he was lying in. The blankets were smooth and soft. The air held a slight tint of disinfectant. It appeared he had been brought to some sort of hospital.

He gripped the sheets much tighter as a momentary wave of panic tightened his chest. Hospitals were _bad_, these humans could find out he wasn't like them… The Doctor forced his heavy eyelids open and blearily tried to look for an escape route. He jerked his arms, and was startled to find them stuck firmly to the bed, though there wasn't any apparent mechanism holding them down.

_Okay, think think think, this is _not _the hardest place you've escaped from_, the Doctor thought. He tugged his arms experimentally, and was once again unsuccessful in moving them even an inch. He had to get going, had to leave before anyone found out…

"Oh, professor, you're awake!" said a voice to his right. The Doctor turned his head to see the slightly fuzzy outline of a lady he recalled meeting briefly. The school nurse. What was her name again? Polly? Poppy?

The Doctor was going to politely ask her to remind him of her name, but instead he heard himself say "I can't move my arms."

The woman bent over him, putting her hand on his forehead to test his temperature. "It was best to restrain you so you didn't hurt yourself during your...episode. Now if you'll just wait one moment..." She pulled her wand out of her crisp white apron and murmured some spell over his wrists. Instantly the Doctor tried to push himself into a sitting position, though his head spun oddly and black dots appeared in his vision with the sudden movement. The woman..._Pomfrey! Yes, that's it, it's Pomfrey_...tutted anxiously and pushed him back down onto the bed. "No, not so quickly, you'll hurt yourself. You haven't had anything to eat for a day and a half, so you must be starving. I'll be right back with some soup for you." Madame Pomfrey bustled away, while the Doctor pushed himself back up, albeit in a much more tentative manner. When the nurse returned with a bowl and spoon in hand, the Doctor tried to open his mouth to ask all the questions he had, but was stopped by the sudden insertion of warm soup into his mouth.

"No. Eat first, questions later. I know your kind," Pomfrey said, her authoritative tone brokering no argument.

"My kind…?" the Doctor asked, quickly swallowing the soup and shifting nervously. If she knew he wasn't human, then the game was up and he'd have to try and find the TARDIS and escape.

"You'll be trying to get up and about even though you _should _be resting. And you'll do the exact opposite of what I say, since you're too eager to get on with regular business even though _doing what I say _will heal you faster than jumping around while you're still half dead."

The Doctor blinked. Oh. He knew that so far, Hogwarts didn't seem to follow conventional human standards, but he'd thought that maybe it their medicine would be more similar to normal human technology. Apparently, wizard medicine did not even extend to the use of a stethoscope.

So he was safe. For now, at least.

"Eat the rest of your soup, goodness knows you need the calories," Pomfrey said, gesturing for him to take the bowl and spoon. As soon as he had them, she walked to the next bed to harass the occupant for not taking his bone-knitting potion. The Doctor quickly gulped down the soup and began focusing intently on rebuilding his mental walls so he could think easier. When the last straggling bits of his headache had been firmly ensconced, he swung his feet over the side of his bed and pulled his shoes back on.

"And just _what_ do you think _you're _doing?" said Pomfrey, appearing out of the blue right at his side.

The Doctor gave her his most charming smile. "Oh, you know me, always on the move. Got some things to take care of. No big deal."

Madame Pomfrey was, a bit unsurprisingly, not convinced. "Hmph! You get dragged in here, in the middle of a seizure, with Professor Snape saying you've been in conniving with a dangerous villain, and think I'll let you go after just a bowl of soup? You, sir, are very much mistaken."

"Wait a minute, hold on, Snape said _what?_" the Doctor asked, brow furrowing in concern and confusion. "Conniving? I was being _attacked!_"

"That's not what the professor said. He said he'd heard you discussing an unknown plot with some source outside of Hogwarts, and that your seizure could have been because of an argument."

"Now that's just completely unfair. Did anyone even think to ask _me _what happened, or were you just going to take his word for it? What sort of a system _is _this?" The Doctor ruffled his hair exasperatedly. "You people are more backwards than the Monpiis, and they convict people for being red heads. If you're _interested_, what actually happened was that someone I used to know has apparently gained psychic abilities, and has been using them to make finding him as difficult as possible for me. Hence the seizure."

"I'm sorry Doctor, but that doesn't make your incident any less suspicious. And...a cumulative examination of your actions this year...well. The Headmaster has asked that you stay here until he can come talk to you."

The Doctor was going to complain about the absolute injustice of this, but was distracted by an odd twinge in his stomach. It wasn't nausea exactly, but more like the feeling he got when he tipped a chair back too far and it teetered on falling over completely. Madame Pomfrey seemed to recognize the twist of discomfort on his face. "Doctor?" she asked. "Are you feeling alright?"

"Yes, I'm fine," the Doctor said, swatting her fluttering hands away. "It's just… it feels like there's something important… "

"I'm sure it's nothing, just some queasiness left over from your episode."

"No," the Doctor said forcefully. "This is different. This is… a point. A set point in time is coming. Coming fast. As in 'next twenty four hours' fast. I can feel it getting closer."

Madame Pomfrey looked at him worriedly. "Hm… I believe I'll fetch you something for nausea. And maybe a sleeping potion."

"I'm not crazy!" the Doctor said, reaching out and grabbing her wrist as she turned away. "I need to speak to Professor Dumbledore. As soon as possible."

"And what exactly would you like to speak to me about?"

The Doctor turned sharply to the right. Albus Dumbledore had entered the Hospital Wing, with his characteristic small smile noticeably absent and his eyes lacking their usual twinkle. Instead, there were dark circles under his half-moon glasses and he carried a distinct air of weariness about him.

"Professor Dumbledore, sir," the Doctor started, but he was cut off by a gesture of the headmaster's crippled hand.

"Poppy, it just so happens that I have a few questions for the Doctor here as well. Would you mind if we stepped into your office for a few minutes?" Dumbledore asked the nurse.

"He really shouldn't be on his feet yet…" Madame Pomfrey protested, but the Doctor had already jumped up and ducked into the small office in the corner of the wing. A few moments later, Dumbledore joined him after flicking the lights on and closing the door with a click.

"Headmaster, you should know - " the Doctor tried to begin again, but was once again interrupted.

"Doctor, you have not been honest with me."

The Doctor sighed. "Alright, listen, I've actually been very honest given the circumstances. There's technically nothing I've lied about."

"From most people's point of view, half-truths constitute lies as much as blatant dishonesty. And this year, Doctor, I would wager there are very few things you've said that were not half-truths."

The Doctor rubbed his eyes. "Well, I really do doubt that you would believe much of what I said even if I did tell you the full truth." Dumbledore fixed him with a hard stare, but did not speak, so the Doctor continued. "No, I'm not technically a 'muggle', even though I'm not a wizard or witch or whatnot. I didn't just step into an enchanted box to get here, but I'm not a 'death eater' or an agent of Voldemort or anything. Really, this is all just a very, very big misunderstanding. But you've got to trust me, this is _not _ the biggest problem you have to deal with tonight. I've made some very...unsettling discoveries that really are more my problem than yours, and also...I have a feeling about tonight. Something big is coming. Tonight is going to be a turning point. And whatever it is, it's not going to be pretty."

Dumbledore heaved a tired-sounding sigh. "And did you get this information from the contact you have outside of school?"

"No! I just know...alright, that sounds flimsy. How about this - clearly, I'm not like you wizards, right? I… oh! This winter. When that Katie girl was attacked, I picked up that necklace that should have killed me, but nothing happened. That proves that, biologically, I'm a bit different, right? Well, I've got this… sense, I guess you could say, that gives me a heads up when something big is about to happen. Sort of a built in alarm system. And I'm telling you, there's something coming tonight that none of us are going to like."

Dumbledore remained silent for a long time. The Doctor was about to try explaining himself further when Dumbledore finally spoke. "Tonight I am taking Harry on a dangerous journey. A necessary journey, to be sure, but a dangerous one. The results of this journey could tip the scales in the war against Voldemort."

"Headmaster… I'm not sure that's wise. This feeling I have isn't an optimistic one."

"And as I said, the journey is necessary. And imperative that it happens tonight." Dumbledore paused. "I see that there is nothing else you are going to tell me tonight." The Doctor shook his head. "Then I must ask you to stay in the Hospital Wing until I can return and we can have a much longer discussion about what exactly you are doing here."

"What? No, you don't understand, something is going to happen. Something bad. I need to be there to stop it," the Doctor said anxiously.

Dumbledore held up a hand to silence him. "Anything that might happen can certainly be prevented by the highly accomplished teachers we have guarding the school."

"But sir…I'm sorry, but I can't promise that I will stay here."

Dumbledore's tired eyes seemed to blaze. "Then I am afraid I will be forced to enchant the school walls to keep you contained inside the building." He looked down at his watch made of spinning planets. "I sent Harry to fetch his invisibility cloak a few minutes ago, so he surely has found it and informed his friends of what he is doing by now." His entire countenance seemed more weighed down than ever. "I am sorry that it has to be this way, for the safety of our students. Farewell, Doctor." He swept out of the room.

The Doctor waited a few seconds, extremely frustrated by the unfortunate turn of events. When he finally emerged from the office, Madame Pomfrey was immediately set upon him, pulling him back to his bed and shoving him down onto it, all the while trying to get him to swallow a sleeping potion that he absolutely refused to take. He may have been stuck there, but that didn't mean he couldn't keep his mind going, trying to think of a way to escape.

A few hours later, the floor beneath him shook, jolting him out of his reverie.

"What was that?" said a sleepy student in the bed beside him, rubbing his eyes and yawning. "Felt like a bloody earthquake…"

The Doctor shot out of bed when the sound of screams echoed up from downstairs, followed by the distinct sound of an explosion. Pomfrey ran over to him, but he shoved her away.

"Please," he begged. "You have to let me go down there, people might be hurt and I can help them. Something awful is happening…I can feel it…you have to let me help them!"

The signs of an internal struggle crossed the nurse's face, but after a few seconds she released the grip she had on the Doctor's shoulder. Without even pausing to thank her, the Doctor sprang for the door and tore down the hallway, where he could see smoke rising from a hole in the floor and shouts coming from below.

The insistent nag in his belly grew and grew, until he could scarcely stand it. The bad premonition he had felt earlier was finally happening. And now…now it was time to end it.

**A/N: I considered actually revealing who the 'voice' was in this chapter, but I've probably given enough hints that you can probably guess it at this point. Next chapter is probably where all the action is finally going to start. Although I'm going to marching band camp next week (playing the baritone lol im gonna die) and so it might be a while before the next chapter is up. Sorry about that.**


	17. Chapter 17

CHAPTER 17

The stone floor shook as a loud crash from the room below reverberated throughout the school, followed by a shout of either pain or rage. The Doctor couldn't tell which as he rushed down the hallway and desperately tried to remember how to reach the main stairway from the hospital wing. He almost flew right by the correct hallway in his mad dash towards the battle, and he nearly plowed directly into the wall in his effort to skid around the corner. The Doctor shook his head and ran to the rotating staircases, which had stopped moving mid-transition, leaving large gaps of space between the different levels. A cluster of frightened first year students were huddled together on the landing. One small girl shrieked as a bolt of green light flew past them and she buried her head into another boy's shoulder.

"Professor!" one of the students cried, her brown eyes filled with tears. "Professor, what's happening? Who's down there?"

The Doctor crouched down and rubbed her back. "Hey, hey, it's all right. I'm going down there to make sure it's all okay. I need you to do something for me, though." The girl nodded at him, making her black curly hair bounce up and down. "I need you all to get out of here and head towards the hospital wing. Can you do that? Okay, good, allons-y!" The children scrambled to their feet and back down the hallway the Doctor had come from.

Once he was sure the children were far away from the commotion below, the Doctor judged the distance between the staircases. He frowned as his estimation amounted to a distance a bit too long for him to jump. _Maybe since gravity is on my side, I could make it_, he thought, but he still hesitated at the ledge.

Another shout from below, followed by several cries of dismay. Before he could fully process what he was doing, he backed up a few steps and launched himself into the air.

For a millisecond, it looked as though he might clear the distance, but he fell just a few centimeters short. The Doctor instinctively threw his hands up to try and grab on to the railing as he plummeted past the staircase. His hand slipped off the handrail, but he managed to grip onto the base of the stone steps before he fell the rest of the distance to the hard ground far below. Panting heavily as he dangled in the air, just a few seconds away from free-falling his way to either death or many, many broken bones, the Doctor tried to get a good look at the next staircase that seemed to be almost directly beneath him. It looked about six meters away. He didn't want to think too much about what he was doing, so he let go and braced himself for the crash.

The air whistled past him before he crashed onto the unforgiving stone below, and instead of sticking the landing as he'd planned, his momentum made him topple down the stairs. He crashed into the wall and lay in a stunned heap for a moment. When the ceiling stopped swirling in front of him, he rolled over and used the rail to pull himself up. A grateful glance at the path ahead of him showed that these stairs were much closer together and well within anyone's jumping capability. After giving himself one more second to clear his head, he hurried down the stairs and made his way to the commotion.

"Duck!" shouted a hoarse voice to his left. Instinctively, the Doctor dropped. A stream of green light passed over his head and hit the wall behind him. There was a brief echo of cracking rock.

The Doctor looked towards where the curse had come from. A tall blond man was running away from the scene and firing more green curses into a mass of dueling wizards made up of adults and children alike. Flashes and bangs erupted periodically as the black-robed intruders pressed ever closer towards the staircase leading up to the Astronomy tower, while students and some adults the Doctor had never seen before countered the attacks and tried to force them back.

A hand appeared at the Doctor's elbow. He looked up into the scarred face of a man wearing shabby robes. "Are you hurt?" the man asked quickly.

"Oh, nah, I'm fine, what's happening here?" the Doctor asked.

"There's no time to explain - we have to defend the school from the Death Eaters." The man helped the Doctor to his feet then ran after the blond attacker with his wand brandished in front of him.

"Oh, is that it?" the Doctor muttered as he dashed into the fray. There were lots of shouts, though he couldn't make out specific sentences. He thought he heard the names "Dumbledore" and "Draco" as two curses whizzed past him.

"Somebody help! Over here!" shouted a voice. The Doctor saw a young woman trying to pull an enormous man away from a fallen body. "Stop it - get off him…!" she yelled. The man snarled and grabbed her arms. His eyes had a feral gleam to them and his mouth and hands were smeared with deep red blood.

The Doctor was there in an instant. He whipped out his sonic screwdriver and jabbed it into the man's spine. The man howled as volts of electricity assaulted his body. After a few seconds, he released the woman's arms and scampered away. The Doctor was tempted to follow him, but his more immediate concern was the still body on the floor. The wounded young man was bleeding in multiple places and his face was covered in what looked like bite marks, but the Doctor could feel a hammering pulse in his throat.

"His name is Bill - is he…?"

The Doctor looked up, and was surprised to see that the woman's eyes had actually changed from brown to blue as she looked at him fearfully. "He's still alive, but he needs a doctor. A proper doctor, mind you, not me."

The woman's eyes switched back to brown as she visibly relaxed. "Get him out of here while we take care of the Death Eaters," she said forcefully. She turned to counter an attack from another dark figure and led him away from the Doctor and Bill.

"I _just _said not me, a real doctor!" the Doctor shouted after her, but she was already gone. "Why does no one _ever_ listen to me?" he asked Bill, who predictably did not answer.

A stray spell sent a spray of dust and rocks over them, and the Doctor threw himself over Bill to protect him from further injury. A sharp shard caught him over the eye and opened up a cut on his forehead. He swiped the blood out of his vision as he twisted the settings on the screwdriver.

"33D, 33E...here we go, 33F," he said, and passed the blue light over the deep gouges on Bill's face. Bill grunted as the wounds were sanitized, but otherwise didn't respond. The Doctor tucked his hands underneath Bill's armpits and started to drag him away from the main conflict.

"_They're breaking away!_" yelled a desperate voice. _Ron_, the Doctor thought.

"Don't let them up the stairs - "

"Those four are - "

"Watch it!"

The Doctor lost his grip on Bill as someone boomed an incantation that sent out a pressure wave across the hallway. In the instant that he was distracted, one of the attacking Death Eaters appeared at his side.

"Going somewhere?" he sneered. He raised his wand and brought it down in a violent slashing motion. The Doctor dove out of the way as a column of fire blazed past where he had been standing. Before the Death Eater had time to attack again, he bounded up and caught the man's wrist.

"Oi! Careful! You'll put someone's eye out, flapping around like that!" the Doctor warned as he squeezed his hand and forced the man to drop his wand. He then quickly pressed his fingertips against the man's temples and sent him to sleep. The Death Eater's eyes rolled up in their sockets. He slumped forward and would have crashed to the ground if the Doctor hadn't caught him and gently lowered him down.

A sharp crack sounded from the main stairs the Death Eaters had been trying to surmount. Neville, it seemed, had tried to pursue them and had been thrown back. "There's some sort of invisible barrier they've put up. We can't get through it!" Neville said as the woman with the changing eyes helped him to his feet.

"There must be _some _way to get past it…" said the scarred man as he aimed a bolt of blue light at the blond Death Eater that had descended on Neville.

The Doctor shoved his hands underneath Bill's arms and dragged him to the wall, where he hopefully would be at least a little safer. Then he hurried to the stairs where the invisible barrier was. In the few free seconds he had while the Death Eaters were engaged with the wizards, he scanned the barrier for any anomalies.

"It looks like they've constructed some sort of electromagnetic repulsion field, though I don't know where they could possibly be getting the energy from, given its size…" the Doctor said, mainly to himself.

"Incoming!" a voice shouted. The Doctor jumped aside as another green curse rocketed past him and disintegrated against the barrier. Ginny Weasley appeared next to him, breathless from the fight. "Can you get rid of it?" she asked.

"Give me some time and I'll think of something," the Doctor assured her.

Ginny nodded. "I'll cover you," she said. She held her wand protectively against her chest as she scanned the fight for any oncoming attackers.

The Doctor knelt down and began twirling the settings of the sonic screwdriver. "The electromagnetic field is rotating in one specific direction, which is keeping us from breaching it," he babbled. "If I was to reverse the direction of the electron flow, I _think_ it would give us a split second to destroy it before the electrons get going in the opposite direction…"

Ginny lashed out her wand against a curse coming their way. "What do you need, professor?"

The Doctor stood and pulled her closer to whisper into her ear. "I'm going to cause a distraction. I need you to be ready to send any sort of destructive spell through the barrier when I say so. Oh, and I'll need your wand."

Ginny's eyes widened, but she nodded and held out her wand. The Doctor took it and turned it over in his hands. "Well, it's not exactly _sonic_ per say, but this should work," he said. He touched the tips of his sonic screwdriver and the wand together, and then pressed down on the screwdriver's activation button.

Instantly, the two devices produced a shrill keening that seemed to pierce straight through everyone's ear drums. Around the room, the duelists dropped their wands in favor of covering their ears in a frantic attempt to block out the sound. When he was sure everyone was thoroughly incapacitated, he let go of the button and the ringing stopped. Before anyone could get their bearings, he aimed the screwdriver at the barrier and reversed the direction of the electrons. "Now, Ginny!" he said urgently, pressing the wand into her hands.

Her face still screwed in pain against the Doctor's 'distraction', Ginny flung her wand blindly behind her and shot at the barrier. While she managed to hit it with her eyes closed, the hex was aimed high and it collided with the ceiling as well. As the barrier collapsed, the ceiling collapsed with it. When the resulting outburst of energy was released, large chunks of stone were hurled across the room at the barely-recovered wizards.

"Everyone drop!" the Doctor called out in the instant while the rocks sailed through the air. Almost everyone managed to avoid the onslaught, except Neville who took a forceful blow to the head and fell to the ground.

McGonagall was the first on her feet. "Quickly, up the stairs," she started, but the moment she said this, Snape and Malfoy emerged from the other side of the obliterated barrier. It appeared they were being pursued by the group of Death Eaters that had bypassed their defenses earlier. "Let them through! Focus on the Death Eaters!" she commanded.

"It's Harry!" Ginny suddenly said, even as she and the Doctor dodged around a giggling woman firing hexes in their direction. "Look, there he goes - "

The Doctor held her back from chasing after him. "Don't worry about Harry, he'll be all right, focus on keeping yourself safe."

"He'll need help…" Ginny protested.

"I'll go after him since I can't do much else here," the Doctor said. He pushed her back towards the resumed battle. "Go help your friends."

Ginny looked torn as she stared down the hallway Harry had disappeared down, but with a groan she turned away and dashed back into the thick of the fight. The Doctor felt a twinge of guilt that he had really just sent a teenager into probable harm, but he didn't have time to agonize over it. He quickly slipped away to follow Harry and hopefully keep him out of harm's way.

Harry had a large head start on him, but the Doctor had a feeling that he had run outside. His sprint to the front grounds seemed interminable as he didn't know the castle's hallways as well as Harry did. When he finally reached the front doors and saw the burn marks that scored the oak paneling, he feared for the worst. His anxiety mounted as he saw Harry's distant figure dashing after Snape and Malfoy, illuminated by the burning building behind them.

The Doctor couldn't make out exactly what Harry was doing, but he doubled his speed when he saw Snape turn with his wand outstretched. Harry flew backwards and hit the grass hard. Another Death Eater turned his wand on Harry as well, and for a moment Harry doubled over and screamed in pain before Snape pushed the Death Eater away and cut off the spell.

"Snape!" the Doctor shouted, trying to distract him from Harry as he ran across the grass. However Snape's attention was focused solely on Harry, and the Doctor could do nothing as Snape yelled something about being a prince and attacked Harry once again. He closed the last stretch of distance and hurriedly knelt down at Harry's head. Harry seemed to be having trouble focusing on him, and he didn't respond when the Doctor tapped his face gently.

"Doctor," Snape said, his normally cool tone harsh with anger. "If I wasn't in a hurry, I would not hesitate to cut you down where you stand."

"Lucky for me you're in such a hurry, then," the Doctor snarled. Snape's lip twisted into a grotesque sneer. He turned and ran with a dramatic flourish of his robes. The Doctor would have chased him if Harry hadn't needed immediate attention.

In the grass next to him, Harry shook his head as if to clear it, and when he spoke for the first time, his words came out too slurred for the Doctor to understand. He leaned in closer to try and make out what he was saying.

What he heard shocked him more than anything else had that entire night.

"Dead," Harry croaked out. "Dumbled… Dumbledore's dead."

**A/N this chapter wins the most-frustrating-chapter-ever award. what an accomplishment. sorry about the super long wait for this mess ha ha ha**


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